1.48 problem 48
Internal
problem
ID
[8085]
Book
:
Second
order
enumerated
odes
Section
:
section
1
Problem
number
:
48
Date
solved
:
Monday, October 21, 2024 at 04:48:08 PM
CAS
classification
:
[[_2nd_order, _missing_x]]
Solve
\begin{align*} y {y^{\prime \prime }}^{4}+{y^{\prime }}^{2}&=0 \end{align*}
1.48.1 Solved as second order missing x ode
Time used: 48.028 (sec)
This is missing independent variable second order ode. Solved by reduction of order by using
substitution which makes the dependent variable \(y\) an independent variable. Using
\begin{align*} y' &= p \end{align*}
Then
\begin{align*} y'' &= \frac {dp}{dx}\\ &= \frac {dp}{dy}\frac {dy}{dx}\\ &= p \frac {dp}{dy} \end{align*}
Hence the ode becomes
\begin{align*} y p \left (y \right )^{4} \left (\frac {d}{d y}p \left (y \right )\right )^{4}+p \left (y \right )^{2} = 0 \end{align*}
Which is now solved as first order ode for \(p(y)\).
Solving for the derivative gives these ODE’s to solve
\begin{align*}
\tag{1} p^{\prime }&=\frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{p y} \\
\tag{2} p^{\prime }&=\frac {i \left (-p^{2} y^{3}\right )^{{1}/{4}}}{p y} \\
\tag{3} p^{\prime }&=-\frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{p y} \\
\tag{4} p^{\prime }&=-\frac {i \left (-p^{2} y^{3}\right )^{{1}/{4}}}{p y} \\
\end{align*}
Now each of the above is solved
separately.
Solving Eq. (1)
To solve an ode of the form
\begin{equation} M\left ( x,y\right ) +N\left ( x,y\right ) \frac {dy}{dx}=0\tag {A}\end{equation}
We assume there exists a function \(\phi \left ( x,y\right ) =c\) where \(c\) is constant, that
satisfies the ode. Taking derivative of \(\phi \) w.r.t. \(x\) gives
\[ \frac {d}{dx}\phi \left ( x,y\right ) =0 \]
Hence
\begin{equation} \frac {\partial \phi }{\partial x}+\frac {\partial \phi }{\partial y}\frac {dy}{dx}=0\tag {B}\end{equation}
Comparing (A,B) shows
that
\begin{align*} \frac {\partial \phi }{\partial x} & =M\\ \frac {\partial \phi }{\partial y} & =N \end{align*}
But since \(\frac {\partial ^{2}\phi }{\partial x\partial y}=\frac {\partial ^{2}\phi }{\partial y\partial x}\) then for the above to be valid, we require that
\[ \frac {\partial M}{\partial y}=\frac {\partial N}{\partial x}\]
If the above condition is satisfied,
then the original ode is called exact. We still need to determine \(\phi \left ( x,y\right ) \) but at least we know
now that we can do that since the condition \(\frac {\partial ^{2}\phi }{\partial x\partial y}=\frac {\partial ^{2}\phi }{\partial y\partial x}\) is satisfied. If this condition is not
satisfied then this method will not work and we have to now look for an integrating
factor to force this condition, which might or might not exist. The first step is
to write the ODE in standard form to check for exactness, which is
\[ M(y,p) \mathop {\mathrm {d}y}+ N(y,p) \mathop {\mathrm {d}p}=0 \tag {1A} \]
Therefore
\begin{align*} \mathop {\mathrm {d}p} &= \left (\frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{p y}\right )\mathop {\mathrm {d}y}\\ \left (-\frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{p y}\right ) \mathop {\mathrm {d}y} + \mathop {\mathrm {d}p} &= 0 \tag {2A} \end{align*}
Comparing (1A) and (2A) shows that
\begin{align*} M(y,p) &= -\frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{p y}\\ N(y,p) &= 1 \end{align*}
The next step is to determine if the ODE is is exact or not. The ODE is exact when the
following condition is satisfied
\[ \frac {\partial M}{\partial p} = \frac {\partial N}{\partial y} \]
Using result found above gives
\begin{align*} \frac {\partial M}{\partial p} &= \frac {\partial }{\partial p} \left (-\frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{p y}\right )\\ &= -\frac {y^{2}}{2 \left (-p^{2} y^{3}\right )^{{3}/{4}}} \end{align*}
And
\begin{align*} \frac {\partial N}{\partial y} &= \frac {\partial }{\partial y} \left (1\right )\\ &= 0 \end{align*}
Since \(\frac {\partial M}{\partial p} \neq \frac {\partial N}{\partial y}\), then the ODE is not exact. Since the ODE is not exact, we will try to find an
integrating factor to make it exact. Let
\begin{align*} A &= \frac {1}{N} \left (\frac {\partial M}{\partial p} - \frac {\partial N}{\partial y} \right ) \\ &=1\left ( \left ( \frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{p^{2} y}+\frac {y^{2}}{2 \left (-p^{2} y^{3}\right )^{{3}/{4}}}\right ) - \left (0 \right ) \right ) \\ &=-\frac {y^{2}}{2 \left (-p^{2} y^{3}\right )^{{3}/{4}}} \end{align*}
Since \(A\) depends on \(p\), it can not be used to obtain an integrating factor. We will now try a
second method to find an integrating factor. Let
\begin{align*} B &= \frac {1}{M} \left ( \frac {\partial N}{\partial y} - \frac {\partial M}{\partial p} \right ) \\ &=-\frac {p y}{\left (-p^{2} y^{3}\right )^{{1}/{4}}}\left ( \left ( 0\right ) - \left (\frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{p^{2} y}+\frac {y^{2}}{2 \left (-p^{2} y^{3}\right )^{{3}/{4}}} \right ) \right ) \\ &=\frac {1}{2 p} \end{align*}
Since \(B\) does not depend on \(y\), it can be used to obtain an integrating factor. Let the
integrating factor be \(\mu \). Then
\begin{align*} \mu &= e^{\int B \mathop {\mathrm {d}p}} \\ &= e^{\int \frac {1}{2 p}\mathop {\mathrm {d}p} } \end{align*}
The result of integrating gives
\begin{align*} \mu &= e^{\frac {\ln \left (p \right )}{2} } \\ &= \sqrt {p} \end{align*}
\(M\) and \(N\) are now multiplied by this integrating factor, giving new \(M\) and new \(N\) which are called \(\overline {M}\)
and \(\overline {N}\) so not to confuse them with the original \(M\) and \(N\).
\begin{align*} \overline {M} &=\mu M \\ &= \sqrt {p}\left (-\frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{p y}\right ) \\ &= -\frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{\sqrt {p}\, y} \end{align*}
And
\begin{align*} \overline {N} &=\mu N \\ &= \sqrt {p}\left (1\right ) \\ &= \sqrt {p} \end{align*}
So now a modified ODE is obtained from the original ODE which will be exact and can be
solved using the standard method. The modified ODE is
\begin{align*} \overline {M} + \overline {N} \frac { \mathop {\mathrm {d}p}}{\mathop {\mathrm {d}y}} &= 0 \\ \left (-\frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{\sqrt {p}\, y}\right ) + \left (\sqrt {p}\right ) \frac { \mathop {\mathrm {d}p}}{\mathop {\mathrm {d}y}} &= 0 \end{align*}
The following equations are now set up to solve for the function \(\phi \left (y,p\right )\)
\begin{align*} \frac {\partial \phi }{\partial y } &= \overline {M}\tag {1} \\ \frac {\partial \phi }{\partial p } &= \overline {N}\tag {2} \end{align*}
Integrating (2) w.r.t. \(p\) gives
\begin{align*}
\int \frac {\partial \phi }{\partial p} \mathop {\mathrm {d}p} &= \int \overline {N}\mathop {\mathrm {d}p} \\
\int \frac {\partial \phi }{\partial p} \mathop {\mathrm {d}p} &= \int \sqrt {p}\mathop {\mathrm {d}p} \\
\tag{3} \phi &= \frac {2 p^{{3}/{2}}}{3}+ f(y) \\
\end{align*}
Where \(f(y)\) is used for the constant of integration since \(\phi \) is a function
of both \(y\) and \(p\). Taking derivative of equation (3) w.r.t \(y\) gives
\begin{equation}
\tag{4} \frac {\partial \phi }{\partial y} = 0+f'(y)
\end{equation}
But equation (1) says that \(\frac {\partial \phi }{\partial y} = -\frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{\sqrt {p}\, y}\).
Therefore equation (4) becomes
\begin{equation}
\tag{5} -\frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{\sqrt {p}\, y} = 0+f'(y)
\end{equation}
Solving equation (5) for \( f'(y)\) gives
\[
f'(y) = -\frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{\sqrt {p}\, y}
\]
Integrating the above w.r.t \(y\)
gives
\begin{align*}
\int f'(y) \mathop {\mathrm {d}y} &= \int \left ( -\frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{\sqrt {p}\, y}\right ) \mathop {\mathrm {d}y} \\
f(y) &= -\frac {4 \left (-p^{2} y^{3}\right )^{{1}/{4}}}{3 \sqrt {p}}+ c_1 \\
\end{align*}
Where \(c_1\) is constant of integration. Substituting result found above for \(f(y)\) into equation
(3) gives \(\phi \)
\[
\phi = \frac {2 p^{{3}/{2}}}{3}-\frac {4 \left (-p^{2} y^{3}\right )^{{1}/{4}}}{3 \sqrt {p}}+ c_1
\]
But since \(\phi \) itself is a constant function, then let \(\phi =c_2\) where \(c_2\) is new constant and
combining \(c_1\) and \(c_2\) constants into the constant \(c_1\) gives the solution as
\[
c_1 = \frac {2 p^{{3}/{2}}}{3}-\frac {4 \left (-p^{2} y^{3}\right )^{{1}/{4}}}{3 \sqrt {p}}
\]
Solving Eq. (2)
Writing the ode as
\begin{align*} p^{\prime }&=\frac {i \left (-p^{2} y^{3}\right )^{{1}/{4}}}{p y}\\ p^{\prime }&= \omega \left ( y,p\right ) \end{align*}
The condition of Lie symmetry is the linearized PDE given by
\begin{align*} \eta _{y}+\omega \left ( \eta _{p}-\xi _{y}\right ) -\omega ^{2}\xi _{p}-\omega _{y}\xi -\omega _{p}\eta =0\tag {A} \end{align*}
To determine \(\xi ,\eta \) then (A) is solved using ansatz. Making bivariate polynomials of degree 1 to
use as anstaz gives
\begin{align*}
\tag{1E} \xi &= p a_{3}+y a_{2}+a_{1} \\
\tag{2E} \eta &= p b_{3}+y b_{2}+b_{1} \\
\end{align*}
Where the unknown coefficients are
\[
\{a_{1}, a_{2}, a_{3}, b_{1}, b_{2}, b_{3}\}
\]
Substituting equations (1E,2E) and \(\omega \)
into (A) gives
\begin{equation}
\tag{5E} b_{2}+\frac {i \left (-p^{2} y^{3}\right )^{{1}/{4}} \left (b_{3}-a_{2}\right )}{p y}+\frac {\sqrt {-p^{2} y^{3}}\, a_{3}}{p^{2} y^{2}}-\left (-\frac {i \left (-p^{2} y^{3}\right )^{{1}/{4}}}{p \,y^{2}}-\frac {3 i p y}{4 \left (-p^{2} y^{3}\right )^{{3}/{4}}}\right ) \left (p a_{3}+y a_{2}+a_{1}\right )-\left (-\frac {i \left (-p^{2} y^{3}\right )^{{1}/{4}}}{p^{2} y}-\frac {i y^{2}}{2 \left (-p^{2} y^{3}\right )^{{3}/{4}}}\right ) \left (p b_{3}+y b_{2}+b_{1}\right ) = 0
\end{equation}
Putting the above in normal form gives
\[
\frac {-i p^{4} y^{3} a_{3}+3 i p^{3} y^{4} a_{2}-6 i p^{3} y^{4} b_{3}-2 i p^{2} y^{5} b_{2}+4 b_{2} p^{2} y^{2} \left (-p^{2} y^{3}\right )^{{3}/{4}}-i p^{3} y^{3} a_{1}-2 i p^{2} y^{4} b_{1}+4 \left (-p^{2} y^{3}\right )^{{5}/{4}} a_{3}}{4 p^{2} y^{2} \left (-p^{2} y^{3}\right )^{{3}/{4}}} = 0
\]
Setting the numerator to zero gives
\begin{equation}
\tag{6E} -i p^{4} y^{3} a_{3}+3 i p^{3} y^{4} a_{2}-6 i p^{3} y^{4} b_{3}-2 i p^{2} y^{5} b_{2}+4 b_{2} p^{2} y^{2} \left (-p^{2} y^{3}\right )^{{3}/{4}}-i p^{3} y^{3} a_{1}-2 i p^{2} y^{4} b_{1}+4 \left (-p^{2} y^{3}\right )^{{5}/{4}} a_{3} = 0
\end{equation}
Since the PDE has radicals, simplifying gives
\[
p^{2} y^{2} \left (-i p^{2} y a_{3}+3 i p \,y^{2} a_{2}-6 i p \,y^{2} b_{3}-2 i y^{3} b_{2}+4 \left (-p^{2} y^{3}\right )^{{3}/{4}} b_{2}-i p y a_{1}-2 i y^{2} b_{1}-4 \left (-p^{2} y^{3}\right )^{{1}/{4}} y a_{3}\right ) = 0
\]
Looking at the above PDE shows the following
are all the terms with \(\{p, y\}\) in them.
\[
\left \{p, y, \left (-p^{2} y^{3}\right )^{{1}/{4}}, \left (-p^{2} y^{3}\right )^{{3}/{4}}\right \}
\]
The following substitution is now made to be able to
collect on all terms with \(\{p, y\}\) in them
\[
\left \{p = v_{1}, y = v_{2}, \left (-p^{2} y^{3}\right )^{{1}/{4}} = v_{3}, \left (-p^{2} y^{3}\right )^{{3}/{4}} = v_{4}\right \}
\]
The above PDE (6E) now becomes
\begin{equation}
\tag{7E} v_{1}^{2} v_{2}^{2} \left (3 i v_{1} v_{2}^{2} a_{2}-i v_{1}^{2} v_{2} a_{3}-2 i v_{2}^{3} b_{2}-6 i v_{1} v_{2}^{2} b_{3}-i v_{1} v_{2} a_{1}-2 i v_{2}^{2} b_{1}-4 v_{3} v_{2} a_{3}+4 v_{4} b_{2}\right ) = 0
\end{equation}
Collecting
the above on the terms \(v_i\) introduced, and these are
\[
\{v_{1}, v_{2}, v_{3}, v_{4}\}
\]
Equation (7E) now becomes
\begin{equation}
\tag{8E} -i v_{2}^{3} a_{3} v_{1}^{4}+\left (3 i a_{2}-6 i b_{3}\right ) v_{1}^{3} v_{2}^{4}-i a_{1} v_{1}^{3} v_{2}^{3}-2 i b_{2} v_{1}^{2} v_{2}^{5}-2 i b_{1} v_{1}^{2} v_{2}^{4}-4 a_{3} v_{3} v_{1}^{2} v_{2}^{3}+4 v_{4} b_{2} v_{1}^{2} v_{2}^{2} = 0
\end{equation}
Setting each coefficients in (8E) to zero gives the following equations to solve
\begin{align*} -2 i b_{1}&=0\\ -2 i b_{2}&=0\\ -i a_{1}&=0\\ -i a_{3}&=0\\ -4 a_{3}&=0\\ 4 b_{2}&=0\\ 3 i a_{2}-6 i b_{3}&=0 \end{align*}
Solving the above equations for the unknowns gives
\begin{align*} a_{1}&=0\\ a_{2}&=a_{2}\\ a_{3}&=0\\ b_{1}&=0\\ b_{2}&=0\\ b_{3}&=\frac {a_{2}}{2} \end{align*}
Substituting the above solution in the anstaz (1E,2E) (using \(1\) as arbitrary value for any
unknown in the RHS) gives
\begin{align*}
\xi &= y \\
\eta &= \frac {p}{2} \\
\end{align*}
The next step is to determine the canonical coordinates \(R,S\). The
canonical coordinates map \(\left ( y,p\right ) \to \left ( R,S \right )\) where \(\left ( R,S \right )\) are the canonical coordinates which make the original ode
become a quadrature and hence solved by integration.
The characteristic pde which is used to find the canonical coordinates is
\begin{align*} \frac {d y}{\xi } &= \frac {d p}{\eta } = dS \tag {1} \end{align*}
The above comes from the requirements that \(\left ( \xi \frac {\partial }{\partial y} + \eta \frac {\partial }{\partial p}\right ) S(y,p) = 1\). Starting with the first pair of ode’s in (1)
gives an ode to solve for the independent variable \(R\) in the canonical coordinates, where \(S(R)\).
Therefore
\begin{align*} \frac {dp}{dy} &= \frac {\eta }{\xi }\\ &= \frac {\frac {p}{2}}{y}\\ &= \frac {p}{2 y} \end{align*}
This is easily solved to give
\begin{align*} p = c_1 \sqrt {y} \end{align*}
Where now the coordinate \(R\) is taken as the constant of integration. Hence
\begin{align*} R &= \frac {p}{\sqrt {y}} \end{align*}
And \(S\) is found from
\begin{align*} dS &= \frac {dy}{\xi } \\ &= \frac {dy}{y} \end{align*}
Integrating gives
\begin{align*} S &= \int { \frac {dy}{T}}\\ &= \ln \left (y \right ) \end{align*}
Where the constant of integration is set to zero as we just need one solution. Now that \(R,S\) are
found, we need to setup the ode in these coordinates. This is done by evaluating
\begin{align*} \frac {dS}{dR} &= \frac { S_{y} + \omega (y,p) S_{p} }{ R_{y} + \omega (y,p) R_{p} }\tag {2} \end{align*}
Where in the above \(R_{y},R_{p},S_{y},S_{p}\) are all partial derivatives and \(\omega (y,p)\) is the right hand side of the original ode
given by
\begin{align*} \omega (y,p) &= \frac {i \left (-p^{2} y^{3}\right )^{{1}/{4}}}{p y} \end{align*}
Evaluating all the partial derivatives gives
\begin{align*} R_{y} &= -\frac {p}{2 y^{{3}/{2}}}\\ R_{p} &= \frac {1}{\sqrt {y}}\\ S_{y} &= \frac {1}{y}\\ S_{p} &= 0 \end{align*}
Substituting all the above in (2) and simplifying gives the ode in canonical coordinates.
\begin{align*} \frac {dS}{dR} &= \frac {2 \sqrt {y}\, p}{2 i \left (-p^{2} y^{3}\right )^{{1}/{4}}-p^{2}}\tag {2A} \end{align*}
We now need to express the RHS as function of \(R\) only. This is done by solving for \(y,p\) in terms of
\(R,S\) from the result obtained earlier and simplifying. This gives
\begin{align*} \frac {dS}{dR} &= \frac {2 R}{\left (-1+i\right ) \sqrt {2}\, \sqrt {R}-R^{2}} \end{align*}
The above is a quadrature ode. This is the whole point of Lie symmetry method. It converts
an ode, no matter how complicated it is, to one that can be solved by integration when the
ode is in the canonical coordiates \(R,S\).
Since the ode has the form \(\frac {d}{d R}S \left (R \right )=f(R)\), then we only need to integrate \(f(R)\).
\begin{align*} \int {dS} &= \int {\frac {2 R}{i \sqrt {R}\, \sqrt {2}-\sqrt {R}\, \sqrt {2}-R^{2}}\, dR}\\ S \left (R \right ) &= -\frac {\left (4 i \sqrt {2}+4 \sqrt {2}\right ) \sqrt {2}\, \left (\ln \left (\frac {R^{3}+2 R^{{3}/{2}} \sqrt {2}+4}{R^{3}-2 R^{{3}/{2}} \sqrt {2}+4}\right )+2 \arctan \left (\frac {R^{{3}/{2}} \sqrt {2}}{2}+1\right )+2 \arctan \left (\frac {R^{{3}/{2}} \sqrt {2}}{2}-1\right )\right )}{48}-\frac {\left (i \sqrt {2}-\sqrt {2}\right ) \sqrt {2}\, \left (\ln \left (\frac {R^{3}-2 R^{{3}/{2}} \sqrt {2}+4}{R^{3}+2 R^{{3}/{2}} \sqrt {2}+4}\right )+2 \arctan \left (\frac {R^{{3}/{2}} \sqrt {2}}{2}+1\right )+2 \arctan \left (\frac {R^{{3}/{2}} \sqrt {2}}{2}-1\right )\right )}{12}-\frac {\ln \left (R^{6}+16\right )}{3}+\frac {2 i \arctan \left (\frac {R^{3}}{4}\right )}{3} + c_3 \end{align*}
\begin{align*} S \left (R \right )&= \left (-\frac {1}{6}-\frac {i}{6}\right ) \ln \left (\frac {R^{3}+2 R^{{3}/{2}} \sqrt {2}+4}{R^{3}-2 R^{{3}/{2}} \sqrt {2}+4}\right )+\left (\frac {1}{6}-\frac {i}{6}\right ) \ln \left (\frac {R^{3}-2 R^{{3}/{2}} \sqrt {2}+4}{R^{3}+2 R^{{3}/{2}} \sqrt {2}+4}\right )+\frac {2 i \arctan \left (\frac {R^{3}}{4}\right )}{3}-\frac {2 i \arctan \left (\frac {R^{{3}/{2}} \sqrt {2}}{2}-1\right )}{3}-\frac {2 i \arctan \left (\frac {R^{{3}/{2}} \sqrt {2}}{2}+1\right )}{3}+c_3 -\frac {\ln \left (R^{6}+16\right )}{3} \end{align*}
To complete the solution, we just need to transform the above back to \(y,p\) coordinates. This
results in
\begin{align*} \ln \left (y \right ) = \left (-\frac {1}{6}-\frac {i}{6}\right ) \ln \left (\frac {\frac {p^{3}}{y^{{3}/{2}}}+2 \left (\frac {p}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}+4}{\frac {p^{3}}{y^{{3}/{2}}}-2 \left (\frac {p}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}+4}\right )+\left (\frac {1}{6}-\frac {i}{6}\right ) \ln \left (\frac {\frac {p^{3}}{y^{{3}/{2}}}-2 \left (\frac {p}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}+4}{\frac {p^{3}}{y^{{3}/{2}}}+2 \left (\frac {p}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}+4}\right )+\frac {2 i \arctan \left (\frac {p^{3}}{4 y^{{3}/{2}}}\right )}{3}-\frac {2 i \arctan \left (\frac {\left (\frac {p}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}}{2}-1\right )}{3}-\frac {2 i \arctan \left (\frac {\left (\frac {p}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}}{2}+1\right )}{3}+c_3 -\frac {\ln \left (\frac {p^{6}}{y^{3}}+16\right )}{3} \end{align*}
Solving Eq. (3)
To solve an ode of the form
\begin{equation} M\left ( x,y\right ) +N\left ( x,y\right ) \frac {dy}{dx}=0\tag {A}\end{equation}
We assume there exists a function \(\phi \left ( x,y\right ) =c\) where \(c\) is constant, that
satisfies the ode. Taking derivative of \(\phi \) w.r.t. \(x\) gives
\[ \frac {d}{dx}\phi \left ( x,y\right ) =0 \]
Hence
\begin{equation} \frac {\partial \phi }{\partial x}+\frac {\partial \phi }{\partial y}\frac {dy}{dx}=0\tag {B}\end{equation}
Comparing (A,B) shows
that
\begin{align*} \frac {\partial \phi }{\partial x} & =M\\ \frac {\partial \phi }{\partial y} & =N \end{align*}
But since \(\frac {\partial ^{2}\phi }{\partial x\partial y}=\frac {\partial ^{2}\phi }{\partial y\partial x}\) then for the above to be valid, we require that
\[ \frac {\partial M}{\partial y}=\frac {\partial N}{\partial x}\]
If the above condition is satisfied,
then the original ode is called exact. We still need to determine \(\phi \left ( x,y\right ) \) but at least we know
now that we can do that since the condition \(\frac {\partial ^{2}\phi }{\partial x\partial y}=\frac {\partial ^{2}\phi }{\partial y\partial x}\) is satisfied. If this condition is not
satisfied then this method will not work and we have to now look for an integrating
factor to force this condition, which might or might not exist. The first step is
to write the ODE in standard form to check for exactness, which is
\[ M(y,p) \mathop {\mathrm {d}y}+ N(y,p) \mathop {\mathrm {d}p}=0 \tag {1A} \]
Therefore
\begin{align*} \mathop {\mathrm {d}p} &= \left (-\frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{p y}\right )\mathop {\mathrm {d}y}\\ \left (\frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{p y}\right ) \mathop {\mathrm {d}y} + \mathop {\mathrm {d}p} &= 0 \tag {2A} \end{align*}
Comparing (1A) and (2A) shows that
\begin{align*} M(y,p) &= \frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{p y}\\ N(y,p) &= 1 \end{align*}
The next step is to determine if the ODE is is exact or not. The ODE is exact when the
following condition is satisfied
\[ \frac {\partial M}{\partial p} = \frac {\partial N}{\partial y} \]
Using result found above gives
\begin{align*} \frac {\partial M}{\partial p} &= \frac {\partial }{\partial p} \left (\frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{p y}\right )\\ &= \frac {y^{2}}{2 \left (-p^{2} y^{3}\right )^{{3}/{4}}} \end{align*}
And
\begin{align*} \frac {\partial N}{\partial y} &= \frac {\partial }{\partial y} \left (1\right )\\ &= 0 \end{align*}
Since \(\frac {\partial M}{\partial p} \neq \frac {\partial N}{\partial y}\), then the ODE is not exact. Since the ODE is not exact, we will try to find an
integrating factor to make it exact. Let
\begin{align*} A &= \frac {1}{N} \left (\frac {\partial M}{\partial p} - \frac {\partial N}{\partial y} \right ) \\ &=1\left ( \left ( -\frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{p^{2} y}-\frac {y^{2}}{2 \left (-p^{2} y^{3}\right )^{{3}/{4}}}\right ) - \left (0 \right ) \right ) \\ &=\frac {y^{2}}{2 \left (-p^{2} y^{3}\right )^{{3}/{4}}} \end{align*}
Since \(A\) depends on \(p\), it can not be used to obtain an integrating factor. We will now try a
second method to find an integrating factor. Let
\begin{align*} B &= \frac {1}{M} \left ( \frac {\partial N}{\partial y} - \frac {\partial M}{\partial p} \right ) \\ &=\frac {p y}{\left (-p^{2} y^{3}\right )^{{1}/{4}}}\left ( \left ( 0\right ) - \left (-\frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{p^{2} y}-\frac {y^{2}}{2 \left (-p^{2} y^{3}\right )^{{3}/{4}}} \right ) \right ) \\ &=\frac {1}{2 p} \end{align*}
Since \(B\) does not depend on \(y\), it can be used to obtain an integrating factor. Let the
integrating factor be \(\mu \). Then
\begin{align*} \mu &= e^{\int B \mathop {\mathrm {d}p}} \\ &= e^{\int \frac {1}{2 p}\mathop {\mathrm {d}p} } \end{align*}
The result of integrating gives
\begin{align*} \mu &= e^{\frac {\ln \left (p \right )}{2} } \\ &= \sqrt {p} \end{align*}
\(M\) and \(N\) are now multiplied by this integrating factor, giving new \(M\) and new \(N\) which are called \(\overline {M}\)
and \(\overline {N}\) so not to confuse them with the original \(M\) and \(N\).
\begin{align*} \overline {M} &=\mu M \\ &= \sqrt {p}\left (\frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{p y}\right ) \\ &= \frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{\sqrt {p}\, y} \end{align*}
And
\begin{align*} \overline {N} &=\mu N \\ &= \sqrt {p}\left (1\right ) \\ &= \sqrt {p} \end{align*}
So now a modified ODE is obtained from the original ODE which will be exact and can be
solved using the standard method. The modified ODE is
\begin{align*} \overline {M} + \overline {N} \frac { \mathop {\mathrm {d}p}}{\mathop {\mathrm {d}y}} &= 0 \\ \left (\frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{\sqrt {p}\, y}\right ) + \left (\sqrt {p}\right ) \frac { \mathop {\mathrm {d}p}}{\mathop {\mathrm {d}y}} &= 0 \end{align*}
The following equations are now set up to solve for the function \(\phi \left (y,p\right )\)
\begin{align*} \frac {\partial \phi }{\partial y } &= \overline {M}\tag {1} \\ \frac {\partial \phi }{\partial p } &= \overline {N}\tag {2} \end{align*}
Integrating (2) w.r.t. \(p\) gives
\begin{align*}
\int \frac {\partial \phi }{\partial p} \mathop {\mathrm {d}p} &= \int \overline {N}\mathop {\mathrm {d}p} \\
\int \frac {\partial \phi }{\partial p} \mathop {\mathrm {d}p} &= \int \sqrt {p}\mathop {\mathrm {d}p} \\
\tag{3} \phi &= \frac {2 p^{{3}/{2}}}{3}+ f(y) \\
\end{align*}
Where \(f(y)\) is used for the constant of integration since \(\phi \) is a function
of both \(y\) and \(p\). Taking derivative of equation (3) w.r.t \(y\) gives
\begin{equation}
\tag{4} \frac {\partial \phi }{\partial y} = 0+f'(y)
\end{equation}
But equation (1) says that \(\frac {\partial \phi }{\partial y} = \frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{\sqrt {p}\, y}\).
Therefore equation (4) becomes
\begin{equation}
\tag{5} \frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{\sqrt {p}\, y} = 0+f'(y)
\end{equation}
Solving equation (5) for \( f'(y)\) gives
\[
f'(y) = \frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{\sqrt {p}\, y}
\]
Integrating the above w.r.t \(y\)
gives
\begin{align*}
\int f'(y) \mathop {\mathrm {d}y} &= \int \left ( \frac {\left (-p^{2} y^{3}\right )^{{1}/{4}}}{\sqrt {p}\, y}\right ) \mathop {\mathrm {d}y} \\
f(y) &= \frac {4 \left (-p^{2} y^{3}\right )^{{1}/{4}}}{3 \sqrt {p}}+ c_4 \\
\end{align*}
Where \(c_4\) is constant of integration. Substituting result found above for \(f(y)\) into equation
(3) gives \(\phi \)
\[
\phi = \frac {2 p^{{3}/{2}}}{3}+\frac {4 \left (-p^{2} y^{3}\right )^{{1}/{4}}}{3 \sqrt {p}}+ c_4
\]
But since \(\phi \) itself is a constant function, then let \(\phi =c_2\) where \(c_2\) is new constant and
combining \(c_4\) and \(c_2\) constants into the constant \(c_4\) gives the solution as
\[
c_4 = \frac {2 p^{{3}/{2}}}{3}+\frac {4 \left (-p^{2} y^{3}\right )^{{1}/{4}}}{3 \sqrt {p}}
\]
Solving Eq. (4)
Writing the ode as
\begin{align*} p^{\prime }&=-\frac {i \left (-p^{2} y^{3}\right )^{{1}/{4}}}{p y}\\ p^{\prime }&= \omega \left ( y,p\right ) \end{align*}
The condition of Lie symmetry is the linearized PDE given by
\begin{align*} \eta _{y}+\omega \left ( \eta _{p}-\xi _{y}\right ) -\omega ^{2}\xi _{p}-\omega _{y}\xi -\omega _{p}\eta =0\tag {A} \end{align*}
To determine \(\xi ,\eta \) then (A) is solved using ansatz. Making bivariate polynomials of degree 1 to
use as anstaz gives
\begin{align*}
\tag{1E} \xi &= p a_{3}+y a_{2}+a_{1} \\
\tag{2E} \eta &= p b_{3}+y b_{2}+b_{1} \\
\end{align*}
Where the unknown coefficients are
\[
\{a_{1}, a_{2}, a_{3}, b_{1}, b_{2}, b_{3}\}
\]
Substituting equations (1E,2E) and \(\omega \)
into (A) gives
\begin{equation}
\tag{5E} b_{2}-\frac {i \left (-p^{2} y^{3}\right )^{{1}/{4}} \left (b_{3}-a_{2}\right )}{p y}+\frac {\sqrt {-p^{2} y^{3}}\, a_{3}}{p^{2} y^{2}}-\left (\frac {i \left (-p^{2} y^{3}\right )^{{1}/{4}}}{p \,y^{2}}+\frac {3 i p y}{4 \left (-p^{2} y^{3}\right )^{{3}/{4}}}\right ) \left (p a_{3}+y a_{2}+a_{1}\right )-\left (\frac {i \left (-p^{2} y^{3}\right )^{{1}/{4}}}{p^{2} y}+\frac {i y^{2}}{2 \left (-p^{2} y^{3}\right )^{{3}/{4}}}\right ) \left (p b_{3}+y b_{2}+b_{1}\right ) = 0
\end{equation}
Putting the above in normal form gives
\[
\frac {i p^{4} y^{3} a_{3}-3 i p^{3} y^{4} a_{2}+6 i p^{3} y^{4} b_{3}+2 i p^{2} y^{5} b_{2}+4 b_{2} p^{2} y^{2} \left (-p^{2} y^{3}\right )^{{3}/{4}}+i p^{3} y^{3} a_{1}+2 i p^{2} y^{4} b_{1}+4 \left (-p^{2} y^{3}\right )^{{5}/{4}} a_{3}}{4 p^{2} y^{2} \left (-p^{2} y^{3}\right )^{{3}/{4}}} = 0
\]
Setting the numerator to zero gives
\begin{equation}
\tag{6E} i p^{4} y^{3} a_{3}-3 i p^{3} y^{4} a_{2}+6 i p^{3} y^{4} b_{3}+2 i p^{2} y^{5} b_{2}+4 b_{2} p^{2} y^{2} \left (-p^{2} y^{3}\right )^{{3}/{4}}+i p^{3} y^{3} a_{1}+2 i p^{2} y^{4} b_{1}+4 \left (-p^{2} y^{3}\right )^{{5}/{4}} a_{3} = 0
\end{equation}
Since the PDE has radicals, simplifying gives
\[
p^{2} y^{2} \left (i p^{2} y a_{3}-3 i p \,y^{2} a_{2}+6 i p \,y^{2} b_{3}+2 i y^{3} b_{2}+4 \left (-p^{2} y^{3}\right )^{{3}/{4}} b_{2}+i p y a_{1}+2 i y^{2} b_{1}-4 \left (-p^{2} y^{3}\right )^{{1}/{4}} y a_{3}\right ) = 0
\]
Looking at the above PDE shows the following
are all the terms with \(\{p, y\}\) in them.
\[
\left \{p, y, \left (-p^{2} y^{3}\right )^{{1}/{4}}, \left (-p^{2} y^{3}\right )^{{3}/{4}}\right \}
\]
The following substitution is now made to be able to
collect on all terms with \(\{p, y\}\) in them
\[
\left \{p = v_{1}, y = v_{2}, \left (-p^{2} y^{3}\right )^{{1}/{4}} = v_{3}, \left (-p^{2} y^{3}\right )^{{3}/{4}} = v_{4}\right \}
\]
The above PDE (6E) now becomes
\begin{equation}
\tag{7E} v_{1}^{2} v_{2}^{2} \left (-3 i v_{1} v_{2}^{2} a_{2}+i v_{1}^{2} v_{2} a_{3}+2 i v_{2}^{3} b_{2}+6 i v_{1} v_{2}^{2} b_{3}+i v_{1} v_{2} a_{1}+2 i v_{2}^{2} b_{1}-4 v_{3} v_{2} a_{3}+4 v_{4} b_{2}\right ) = 0
\end{equation}
Collecting
the above on the terms \(v_i\) introduced, and these are
\[
\{v_{1}, v_{2}, v_{3}, v_{4}\}
\]
Equation (7E) now becomes
\begin{equation}
\tag{8E} i v_{2}^{3} a_{3} v_{1}^{4}+\left (-3 i a_{2}+6 i b_{3}\right ) v_{1}^{3} v_{2}^{4}+i a_{1} v_{1}^{3} v_{2}^{3}+2 i b_{2} v_{1}^{2} v_{2}^{5}+2 i b_{1} v_{1}^{2} v_{2}^{4}-4 a_{3} v_{3} v_{1}^{2} v_{2}^{3}+4 v_{4} b_{2} v_{1}^{2} v_{2}^{2} = 0
\end{equation}
Setting each coefficients in (8E) to zero gives the following equations to solve
\begin{align*} i a_{1}&=0\\ i a_{3}&=0\\ 2 i b_{1}&=0\\ 2 i b_{2}&=0\\ -4 a_{3}&=0\\ 4 b_{2}&=0\\ -3 i a_{2}+6 i b_{3}&=0 \end{align*}
Solving the above equations for the unknowns gives
\begin{align*} a_{1}&=0\\ a_{2}&=a_{2}\\ a_{3}&=0\\ b_{1}&=0\\ b_{2}&=0\\ b_{3}&=\frac {a_{2}}{2} \end{align*}
Substituting the above solution in the anstaz (1E,2E) (using \(1\) as arbitrary value for any
unknown in the RHS) gives
\begin{align*}
\xi &= y \\
\eta &= \frac {p}{2} \\
\end{align*}
The next step is to determine the canonical coordinates \(R,S\). The
canonical coordinates map \(\left ( y,p\right ) \to \left ( R,S \right )\) where \(\left ( R,S \right )\) are the canonical coordinates which make the original ode
become a quadrature and hence solved by integration.
The characteristic pde which is used to find the canonical coordinates is
\begin{align*} \frac {d y}{\xi } &= \frac {d p}{\eta } = dS \tag {1} \end{align*}
The above comes from the requirements that \(\left ( \xi \frac {\partial }{\partial y} + \eta \frac {\partial }{\partial p}\right ) S(y,p) = 1\). Starting with the first pair of ode’s in (1)
gives an ode to solve for the independent variable \(R\) in the canonical coordinates, where \(S(R)\).
Therefore
\begin{align*} \frac {dp}{dy} &= \frac {\eta }{\xi }\\ &= \frac {\frac {p}{2}}{y}\\ &= \frac {p}{2 y} \end{align*}
This is easily solved to give
\begin{align*} p = c_1 \sqrt {y} \end{align*}
Where now the coordinate \(R\) is taken as the constant of integration. Hence
\begin{align*} R &= \frac {p}{\sqrt {y}} \end{align*}
And \(S\) is found from
\begin{align*} dS &= \frac {dy}{\xi } \\ &= \frac {dy}{y} \end{align*}
Integrating gives
\begin{align*} S &= \int { \frac {dy}{T}}\\ &= \ln \left (y \right ) \end{align*}
Where the constant of integration is set to zero as we just need one solution. Now that \(R,S\) are
found, we need to setup the ode in these coordinates. This is done by evaluating
\begin{align*} \frac {dS}{dR} &= \frac { S_{y} + \omega (y,p) S_{p} }{ R_{y} + \omega (y,p) R_{p} }\tag {2} \end{align*}
Where in the above \(R_{y},R_{p},S_{y},S_{p}\) are all partial derivatives and \(\omega (y,p)\) is the right hand side of the original ode
given by
\begin{align*} \omega (y,p) &= -\frac {i \left (-p^{2} y^{3}\right )^{{1}/{4}}}{p y} \end{align*}
Evaluating all the partial derivatives gives
\begin{align*} R_{y} &= -\frac {p}{2 y^{{3}/{2}}}\\ R_{p} &= \frac {1}{\sqrt {y}}\\ S_{y} &= \frac {1}{y}\\ S_{p} &= 0 \end{align*}
Substituting all the above in (2) and simplifying gives the ode in canonical coordinates.
\begin{align*} \frac {dS}{dR} &= -\frac {2 \sqrt {y}\, p}{2 i \left (-p^{2} y^{3}\right )^{{1}/{4}}+p^{2}}\tag {2A} \end{align*}
We now need to express the RHS as function of \(R\) only. This is done by solving for \(y,p\) in terms of
\(R,S\) from the result obtained earlier and simplifying. This gives
\begin{align*} \frac {dS}{dR} &= -\frac {2 R}{\left (-1+i\right ) \sqrt {2}\, \sqrt {R}+R^{2}} \end{align*}
The above is a quadrature ode. This is the whole point of Lie symmetry method. It converts
an ode, no matter how complicated it is, to one that can be solved by integration when the
ode is in the canonical coordiates \(R,S\).
Since the ode has the form \(\frac {d}{d R}S \left (R \right )=f(R)\), then we only need to integrate \(f(R)\).
\begin{align*} \int {dS} &= \int {-\frac {2 R}{i \sqrt {R}\, \sqrt {2}-\sqrt {R}\, \sqrt {2}+R^{2}}\, dR}\\ S \left (R \right ) &= -\frac {\left (-4 i \sqrt {2}-4 \sqrt {2}\right ) \sqrt {2}\, \left (\ln \left (\frac {R^{3}+2 R^{{3}/{2}} \sqrt {2}+4}{R^{3}-2 R^{{3}/{2}} \sqrt {2}+4}\right )+2 \arctan \left (\frac {R^{{3}/{2}} \sqrt {2}}{2}+1\right )+2 \arctan \left (\frac {R^{{3}/{2}} \sqrt {2}}{2}-1\right )\right )}{48}-\frac {\left (-i \sqrt {2}+\sqrt {2}\right ) \sqrt {2}\, \left (\ln \left (\frac {R^{3}-2 R^{{3}/{2}} \sqrt {2}+4}{R^{3}+2 R^{{3}/{2}} \sqrt {2}+4}\right )+2 \arctan \left (\frac {R^{{3}/{2}} \sqrt {2}}{2}+1\right )+2 \arctan \left (\frac {R^{{3}/{2}} \sqrt {2}}{2}-1\right )\right )}{12}-\frac {\ln \left (R^{6}+16\right )}{3}+\frac {2 i \arctan \left (\frac {R^{3}}{4}\right )}{3} + c_6 \end{align*}
\begin{align*} S \left (R \right )&= \left (\frac {1}{6}+\frac {i}{6}\right ) \ln \left (\frac {R^{3}+2 R^{{3}/{2}} \sqrt {2}+4}{R^{3}-2 R^{{3}/{2}} \sqrt {2}+4}\right )+\left (-\frac {1}{6}+\frac {i}{6}\right ) \ln \left (\frac {R^{3}-2 R^{{3}/{2}} \sqrt {2}+4}{R^{3}+2 R^{{3}/{2}} \sqrt {2}+4}\right )+\frac {2 i \arctan \left (\frac {R^{3}}{4}\right )}{3}+\frac {2 i \arctan \left (\frac {R^{{3}/{2}} \sqrt {2}}{2}-1\right )}{3}+\frac {2 i \arctan \left (\frac {R^{{3}/{2}} \sqrt {2}}{2}+1\right )}{3}+c_6 -\frac {\ln \left (R^{6}+16\right )}{3} \end{align*}
To complete the solution, we just need to transform the above back to \(y,p\) coordinates. This
results in
\begin{align*} \ln \left (y \right ) = \left (\frac {1}{6}+\frac {i}{6}\right ) \ln \left (\frac {\frac {p^{3}}{y^{{3}/{2}}}+2 \left (\frac {p}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}+4}{\frac {p^{3}}{y^{{3}/{2}}}-2 \left (\frac {p}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}+4}\right )+\left (-\frac {1}{6}+\frac {i}{6}\right ) \ln \left (\frac {\frac {p^{3}}{y^{{3}/{2}}}-2 \left (\frac {p}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}+4}{\frac {p^{3}}{y^{{3}/{2}}}+2 \left (\frac {p}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}+4}\right )+\frac {2 i \arctan \left (\frac {p^{3}}{4 y^{{3}/{2}}}\right )}{3}+\frac {2 i \arctan \left (\frac {\left (\frac {p}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}}{2}-1\right )}{3}+\frac {2 i \arctan \left (\frac {\left (\frac {p}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}}{2}+1\right )}{3}+c_6 -\frac {\ln \left (\frac {p^{6}}{y^{3}}+16\right )}{3} \end{align*}
For solution (1) found earlier, since \(p=y^{\prime }\) then we now have a new first order ode to solve which is
\begin{align*} \frac {2 {y^{\prime }}^{{3}/{2}}}{3}-\frac {4 \left (-{y^{\prime }}^{2} y^{3}\right )^{{1}/{4}}}{3 \sqrt {y^{\prime }}} = c_1 \end{align*}
Solving for the derivative gives these ODE’s to solve
\begin{align*}
\tag{1} y^{\prime }&=\frac {{\left (16 \left (-y^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{2}/{3}}}{4} \\
\tag{2} y^{\prime }&={\left (-\frac {{\left (16 \left (-y^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{1}/{3}}}{4}+\frac {i \sqrt {3}\, {\left (16 \left (-y^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{1}/{3}}}{4}\right )}^{2} \\
\tag{3} y^{\prime }&={\left (-\frac {{\left (16 \left (-y^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{1}/{3}}}{4}-\frac {i \sqrt {3}\, {\left (16 \left (-y^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{1}/{3}}}{4}\right )}^{2} \\
\tag{4} y^{\prime }&=\frac {{\left (16 i \left (-y^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{2}/{3}}}{4} \\
\tag{5} y^{\prime }&={\left (-\frac {{\left (16 i \left (-y^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{1}/{3}}}{4}+\frac {i \sqrt {3}\, {\left (16 i \left (-y^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{1}/{3}}}{4}\right )}^{2} \\
\tag{6} y^{\prime }&={\left (-\frac {{\left (16 i \left (-y^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{1}/{3}}}{4}-\frac {i \sqrt {3}\, {\left (16 i \left (-y^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{1}/{3}}}{4}\right )}^{2} \\
\tag{7} y^{\prime }&=\frac {{\left (-16 \left (-y^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{2}/{3}}}{4} \\
\tag{8} y^{\prime }&={\left (-\frac {{\left (-16 \left (-y^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{1}/{3}}}{4}-\frac {i \sqrt {3}\, {\left (-16 \left (-y^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{1}/{3}}}{4}\right )}^{2} \\
\tag{9} y^{\prime }&={\left (-\frac {{\left (-16 \left (-y^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{1}/{3}}}{4}+\frac {i \sqrt {3}\, {\left (-16 \left (-y^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{1}/{3}}}{4}\right )}^{2} \\
\tag{10} y^{\prime }&=\frac {{\left (-16 i \left (-y^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{2}/{3}}}{4} \\
\tag{11} y^{\prime }&={\left (-\frac {{\left (-16 i \left (-y^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{1}/{3}}}{4}-\frac {i \sqrt {3}\, {\left (-16 i \left (-y^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{1}/{3}}}{4}\right )}^{2} \\
\tag{12} y^{\prime }&={\left (-\frac {{\left (-16 i \left (-y^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{1}/{3}}}{4}+\frac {i \sqrt {3}\, {\left (-16 i \left (-y^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{1}/{3}}}{4}\right )}^{2} \\
\end{align*}
Now each of the above is solved
separately.
Solving Eq. (1)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {4}{{\left (16 \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{2}/{3}}}d \tau = x +c_7 \]
Solving Eq. (2)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {16}{{\left (16 \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{2}/{3}} \left (i \sqrt {3}-1\right )^{2}}d \tau = x +c_8 \]
Solving Eq. (3)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {16}{{\left (16 \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{2}/{3}} \left (1+i \sqrt {3}\right )^{2}}d \tau = x +c_9 \]
Solving Eq. (4)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {4}{{\left (16 i \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{2}/{3}}}d \tau = x +\textit {\_C10} \]
Solving Eq. (5)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {16}{{\left (16 i \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{2}/{3}} \left (i \sqrt {3}-1\right )^{2}}d \tau = x +\textit {\_C11} \]
Solving Eq. (6)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {16}{{\left (16 i \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{2}/{3}} \left (1+i \sqrt {3}\right )^{2}}d \tau = x +\textit {\_C12} \]
Solving Eq. (7)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {4}{{\left (-16 \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{2}/{3}}}d \tau = x +\textit {\_C13} \]
Singular solutions
are found by solving
\begin{align*} \frac {{\left (-16 \left (-y^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{2}/{3}}}{4}&= 0 \end{align*}
for \(y\). This is because we had to divide by this in the above step. This gives the following
singular solution(s), which also have to satisfy the given ODE.
\begin{align*} y = \frac {3 \left (-6 c_1 \right )^{{1}/{3}} c_1}{8}\\ y = \frac {3 \left (-\frac {\left (-6 c_1 \right )^{{1}/{3}}}{4}-\frac {i \sqrt {3}\, \left (-6 c_1 \right )^{{1}/{3}}}{4}\right ) c_1}{4}\\ y = \frac {3 \left (-\frac {\left (-6 c_1 \right )^{{1}/{3}}}{4}+\frac {i \sqrt {3}\, \left (-6 c_1 \right )^{{1}/{3}}}{4}\right ) c_1}{4} \end{align*}
Solving Eq. (8)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {16}{{\left (-16 \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{2}/{3}} \left (1+i \sqrt {3}\right )^{2}}d \tau = x +\textit {\_C14} \]
Singular solutions
are found by solving
\begin{align*} \frac {{\left (-16 \left (-y^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{2}/{3}} \left (1+i \sqrt {3}\right )^{2}}{16}&= 0 \end{align*}
for \(y\). This is because we had to divide by this in the above step. This gives the following
singular solution(s), which also have to satisfy the given ODE.
\begin{align*} y = \frac {3 \left (-6 c_1 \right )^{{1}/{3}} c_1}{8}\\ y = \frac {3 \left (-\frac {\left (-6 c_1 \right )^{{1}/{3}}}{4}-\frac {i \sqrt {3}\, \left (-6 c_1 \right )^{{1}/{3}}}{4}\right ) c_1}{4}\\ y = \frac {3 \left (-\frac {\left (-6 c_1 \right )^{{1}/{3}}}{4}+\frac {i \sqrt {3}\, \left (-6 c_1 \right )^{{1}/{3}}}{4}\right ) c_1}{4} \end{align*}
Solving Eq. (9)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {16}{{\left (-16 \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{2}/{3}} \left (i \sqrt {3}-1\right )^{2}}d \tau = x +\textit {\_C15} \]
Singular solutions
are found by solving
\begin{align*} \frac {{\left (-16 \left (-y^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{2}/{3}} \left (i \sqrt {3}-1\right )^{2}}{16}&= 0 \end{align*}
for \(y\). This is because we had to divide by this in the above step. This gives the following
singular solution(s), which also have to satisfy the given ODE.
\begin{align*} y = \frac {3 \left (-6 c_1 \right )^{{1}/{3}} c_1}{8}\\ y = \frac {3 \left (-\frac {\left (-6 c_1 \right )^{{1}/{3}}}{4}-\frac {i \sqrt {3}\, \left (-6 c_1 \right )^{{1}/{3}}}{4}\right ) c_1}{4}\\ y = \frac {3 \left (-\frac {\left (-6 c_1 \right )^{{1}/{3}}}{4}+\frac {i \sqrt {3}\, \left (-6 c_1 \right )^{{1}/{3}}}{4}\right ) c_1}{4} \end{align*}
Solving Eq. (10)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {4}{{\left (-16 i \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{2}/{3}}}d \tau = x +\textit {\_C16} \]
Solving Eq. (11)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {16}{{\left (-16 i \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{2}/{3}} \left (1+i \sqrt {3}\right )^{2}}d \tau = x +\textit {\_C17} \]
Solving Eq. (12)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {16}{{\left (-16 i \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_1 \right )}^{{2}/{3}} \left (i \sqrt {3}-1\right )^{2}}d \tau = x +\textit {\_C18} \]
For solution
(2) found earlier, since \(p=y^{\prime }\) then we now have a new first order ode to solve which is
\begin{align*} \frac {2 {y^{\prime }}^{{3}/{2}}}{3}+\frac {4 \left (-{y^{\prime }}^{2} y^{3}\right )^{{1}/{4}}}{3 \sqrt {y^{\prime }}} = c_4 \end{align*}
Solving for the derivative gives these ODE’s to solve
\begin{align*}
\tag{1} y^{\prime }&=\frac {{\left (16 \left (-y^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{2}/{3}}}{4} \\
\tag{2} y^{\prime }&={\left (-\frac {{\left (16 \left (-y^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{1}/{3}}}{4}+\frac {i \sqrt {3}\, {\left (16 \left (-y^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{1}/{3}}}{4}\right )}^{2} \\
\tag{3} y^{\prime }&={\left (-\frac {{\left (16 \left (-y^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{1}/{3}}}{4}-\frac {i \sqrt {3}\, {\left (16 \left (-y^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{1}/{3}}}{4}\right )}^{2} \\
\tag{4} y^{\prime }&=\frac {{\left (16 i \left (-y^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{2}/{3}}}{4} \\
\tag{5} y^{\prime }&={\left (-\frac {{\left (16 i \left (-y^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{1}/{3}}}{4}+\frac {i \sqrt {3}\, {\left (16 i \left (-y^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{1}/{3}}}{4}\right )}^{2} \\
\tag{6} y^{\prime }&={\left (-\frac {{\left (16 i \left (-y^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{1}/{3}}}{4}-\frac {i \sqrt {3}\, {\left (16 i \left (-y^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{1}/{3}}}{4}\right )}^{2} \\
\tag{7} y^{\prime }&=\frac {{\left (-16 \left (-y^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{2}/{3}}}{4} \\
\tag{8} y^{\prime }&={\left (-\frac {{\left (-16 \left (-y^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{1}/{3}}}{4}-\frac {i \sqrt {3}\, {\left (-16 \left (-y^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{1}/{3}}}{4}\right )}^{2} \\
\tag{9} y^{\prime }&={\left (-\frac {{\left (-16 \left (-y^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{1}/{3}}}{4}+\frac {i \sqrt {3}\, {\left (-16 \left (-y^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{1}/{3}}}{4}\right )}^{2} \\
\tag{10} y^{\prime }&=\frac {{\left (-16 i \left (-y^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{2}/{3}}}{4} \\
\tag{11} y^{\prime }&={\left (-\frac {{\left (-16 i \left (-y^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{1}/{3}}}{4}-\frac {i \sqrt {3}\, {\left (-16 i \left (-y^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{1}/{3}}}{4}\right )}^{2} \\
\tag{12} y^{\prime }&={\left (-\frac {{\left (-16 i \left (-y^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{1}/{3}}}{4}+\frac {i \sqrt {3}\, {\left (-16 i \left (-y^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{1}/{3}}}{4}\right )}^{2} \\
\end{align*}
Now each of the above is solved
separately.
Solving Eq. (1)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {4}{{\left (16 \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{2}/{3}}}d \tau = x +\textit {\_C19} \]
Solving Eq. (2)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {16}{{\left (16 \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{2}/{3}} \left (i \sqrt {3}-1\right )^{2}}d \tau = x +\textit {\_C20} \]
Solving Eq. (3)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {16}{{\left (16 \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{2}/{3}} \left (1+i \sqrt {3}\right )^{2}}d \tau = x +\textit {\_C21} \]
Solving Eq. (4)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {4}{{\left (16 i \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{2}/{3}}}d \tau = x +\textit {\_C22} \]
Solving Eq. (5)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {16}{{\left (16 i \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{2}/{3}} \left (i \sqrt {3}-1\right )^{2}}d \tau = x +\textit {\_C23} \]
Solving Eq. (6)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {16}{{\left (16 i \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{2}/{3}} \left (1+i \sqrt {3}\right )^{2}}d \tau = x +\textit {\_C24} \]
Solving Eq. (7)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {4}{{\left (-16 \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{2}/{3}}}d \tau = x +\textit {\_C25} \]
Singular solutions
are found by solving
\begin{align*} \frac {{\left (-16 \left (-y^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{2}/{3}}}{4}&= 0 \end{align*}
for \(y\). This is because we had to divide by this in the above step. This gives the following
singular solution(s), which also have to satisfy the given ODE.
\begin{align*} y = \frac {3 \left (-6 c_4 \right )^{{1}/{3}} c_4}{8}\\ y = \frac {3 \left (-\frac {\left (-6 c_4 \right )^{{1}/{3}}}{4}-\frac {i \sqrt {3}\, \left (-6 c_4 \right )^{{1}/{3}}}{4}\right ) c_4}{4}\\ y = \frac {3 \left (-\frac {\left (-6 c_4 \right )^{{1}/{3}}}{4}+\frac {i \sqrt {3}\, \left (-6 c_4 \right )^{{1}/{3}}}{4}\right ) c_4}{4} \end{align*}
Solving Eq. (8)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {16}{{\left (-16 \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{2}/{3}} \left (1+i \sqrt {3}\right )^{2}}d \tau = x +\textit {\_C26} \]
Singular solutions
are found by solving
\begin{align*} \frac {{\left (-16 \left (-y^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{2}/{3}} \left (1+i \sqrt {3}\right )^{2}}{16}&= 0 \end{align*}
for \(y\). This is because we had to divide by this in the above step. This gives the following
singular solution(s), which also have to satisfy the given ODE.
\begin{align*} y = \frac {3 \left (-6 c_4 \right )^{{1}/{3}} c_4}{8}\\ y = \frac {3 \left (-\frac {\left (-6 c_4 \right )^{{1}/{3}}}{4}-\frac {i \sqrt {3}\, \left (-6 c_4 \right )^{{1}/{3}}}{4}\right ) c_4}{4}\\ y = \frac {3 \left (-\frac {\left (-6 c_4 \right )^{{1}/{3}}}{4}+\frac {i \sqrt {3}\, \left (-6 c_4 \right )^{{1}/{3}}}{4}\right ) c_4}{4} \end{align*}
Solving Eq. (9)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {16}{{\left (-16 \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{2}/{3}} \left (i \sqrt {3}-1\right )^{2}}d \tau = x +\textit {\_C27} \]
Singular solutions
are found by solving
\begin{align*} \frac {{\left (-16 \left (-y^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{2}/{3}} \left (i \sqrt {3}-1\right )^{2}}{16}&= 0 \end{align*}
for \(y\). This is because we had to divide by this in the above step. This gives the following
singular solution(s), which also have to satisfy the given ODE.
\begin{align*} y = \frac {3 \left (-6 c_4 \right )^{{1}/{3}} c_4}{8}\\ y = \frac {3 \left (-\frac {\left (-6 c_4 \right )^{{1}/{3}}}{4}-\frac {i \sqrt {3}\, \left (-6 c_4 \right )^{{1}/{3}}}{4}\right ) c_4}{4}\\ y = \frac {3 \left (-\frac {\left (-6 c_4 \right )^{{1}/{3}}}{4}+\frac {i \sqrt {3}\, \left (-6 c_4 \right )^{{1}/{3}}}{4}\right ) c_4}{4} \end{align*}
Solving Eq. (10)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {4}{{\left (-16 i \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{2}/{3}}}d \tau = x +\textit {\_C28} \]
Solving Eq. (11)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {16}{{\left (-16 i \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{2}/{3}} \left (1+i \sqrt {3}\right )^{2}}d \tau = x +\textit {\_C29} \]
Solving Eq. (12)
Since initial conditions \(\left (x_0,y_0\right ) \) are given, then the result can be written as Since unable to evaluate
the integral, and no initial conditions are given, then the result becomes
\[ \int _{}^{y}\frac {16}{{\left (-16 i \left (-\tau ^{3}\right )^{{1}/{4}}+12 c_4 \right )}^{{2}/{3}} \left (i \sqrt {3}-1\right )^{2}}d \tau = x +\textit {\_C30} \]
For solution
(3) found earlier, since \(p=y^{\prime }\) then we now have a new first order ode to solve which is
\begin{align*} \ln \left (y\right ) = \left (-\frac {1}{6}-\frac {i}{6}\right ) \ln \left (\frac {\frac {{y^{\prime }}^{3}}{y^{{3}/{2}}}+2 \left (\frac {y^{\prime }}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}+4}{\frac {{y^{\prime }}^{3}}{y^{{3}/{2}}}-2 \left (\frac {y^{\prime }}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}+4}\right )+\left (\frac {1}{6}-\frac {i}{6}\right ) \ln \left (\frac {\frac {{y^{\prime }}^{3}}{y^{{3}/{2}}}-2 \left (\frac {y^{\prime }}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}+4}{\frac {{y^{\prime }}^{3}}{y^{{3}/{2}}}+2 \left (\frac {y^{\prime }}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}+4}\right )+\frac {2 i \arctan \left (\frac {{y^{\prime }}^{3}}{4 y^{{3}/{2}}}\right )}{3}-\frac {2 i \arctan \left (\frac {\left (\frac {y^{\prime }}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}}{2}-1\right )}{3}-\frac {2 i \arctan \left (\frac {\left (\frac {y^{\prime }}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}}{2}+1\right )}{3}+c_3 -\frac {\ln \left (\frac {{y^{\prime }}^{6}}{y^{3}}+16\right )}{3} \end{align*}
Unable to solve. Terminating.
For solution (4) found earlier, since \(p=y^{\prime }\) then we now have a new first order ode to solve which is
\begin{align*} \ln \left (y\right ) = \left (\frac {1}{6}+\frac {i}{6}\right ) \ln \left (\frac {\frac {{y^{\prime }}^{3}}{y^{{3}/{2}}}+2 \left (\frac {y^{\prime }}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}+4}{\frac {{y^{\prime }}^{3}}{y^{{3}/{2}}}-2 \left (\frac {y^{\prime }}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}+4}\right )+\left (-\frac {1}{6}+\frac {i}{6}\right ) \ln \left (\frac {\frac {{y^{\prime }}^{3}}{y^{{3}/{2}}}-2 \left (\frac {y^{\prime }}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}+4}{\frac {{y^{\prime }}^{3}}{y^{{3}/{2}}}+2 \left (\frac {y^{\prime }}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}+4}\right )+\frac {2 i \arctan \left (\frac {{y^{\prime }}^{3}}{4 y^{{3}/{2}}}\right )}{3}+\frac {2 i \arctan \left (\frac {\left (\frac {y^{\prime }}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}}{2}-1\right )}{3}+\frac {2 i \arctan \left (\frac {\left (\frac {y^{\prime }}{\sqrt {y}}\right )^{{3}/{2}} \sqrt {2}}{2}+1\right )}{3}+c_6 -\frac {\ln \left (\frac {{y^{\prime }}^{6}}{y^{3}}+16\right )}{3} \end{align*}
Unable to solve. Terminating.
Will add steps showing solving for IC soon.
1.48.2 Maple step by step solution
1.48.3 Maple trace
Methods for second order ODEs:
1.48.4 Maple dsolve solution
Solving time : 3.087
(sec)
Leaf size : 2829
dsolve(y(x)*diff(diff(y(x),x),x)^4+diff(y(x),x)^2 = 0,
y(x),singsol=all)
\begin{align*}
y &= c_1 \\
y &= 0 \\
\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {\textit {\_a}^{3} \left (2 \textit {\_a} -\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) \left (-2 \textit {\_a}^{3}+\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}}}}d \textit {\_a} -x -c_2 &= 0 \\
\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {-\textit {\_a}^{3} \left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}-2 \textit {\_a} \right ) {\left (\left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}-2 \textit {\_a} \right ) \textit {\_a}^{2}\right )}^{{1}/{3}}}}d \textit {\_a} -x -c_2 &= 0 \\
\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {\textit {\_a}^{3} \left (2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) \left (-2 \textit {\_a}^{3}-\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}}}}d \textit {\_a} -x -c_2 &= 0 \\
\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {\textit {\_a}^{3} \left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}+2 \textit {\_a} \right ) {\left (-\left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}+2 \textit {\_a} \right ) \textit {\_a}^{2}\right )}^{{1}/{3}}}}d \textit {\_a} -x -c_2 &= 0 \\
\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {\left (-2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) \left (1+i \sqrt {3}\right ) \textit {\_a}^{3} \left (-2 \textit {\_a}^{3}+\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}}}}d \textit {\_a} \right )-x -c_2 &= 0 \\
\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {\left (i-\sqrt {3}\right ) \textit {\_a}^{3} {\left (\left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}-2 \textit {\_a} \right ) \textit {\_a}^{2}\right )}^{{1}/{3}} \left (\left (\textit {\_a} c_1 \right )^{{1}/{4}}+2 i \textit {\_a} \right )}}d \textit {\_a} \right )-x -c_2 &= 0 \\
\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {-2 \left (\textit {\_a} +\frac {\left (\textit {\_a} c_1 \right )^{{1}/{4}}}{2}\right ) \left (-2 \textit {\_a}^{3}-\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}} \left (1+i \sqrt {3}\right ) \textit {\_a}^{3}}}d \textit {\_a} \right )-x -c_2 &= 0 \\
\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {-\textit {\_a}^{3} \left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}+2 \textit {\_a} \right ) {\left (-\left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}+2 \textit {\_a} \right ) \textit {\_a}^{2}\right )}^{{1}/{3}} \left (1+i \sqrt {3}\right )}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\left (\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {\textit {\_a}^{3} \left (2 \textit {\_a} -\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) \left (-2 \textit {\_a}^{3}+\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}}}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\left (\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {-\textit {\_a}^{3} \left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}-2 \textit {\_a} \right ) {\left (\left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}-2 \textit {\_a} \right ) \textit {\_a}^{2}\right )}^{{1}/{3}}}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\left (\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {\textit {\_a}^{3} \left (2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) \left (-2 \textit {\_a}^{3}-\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}}}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\left (\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {\textit {\_a}^{3} \left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}+2 \textit {\_a} \right ) {\left (-\left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}+2 \textit {\_a} \right ) \textit {\_a}^{2}\right )}^{{1}/{3}}}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {\left (1-i \sqrt {3}\right ) \textit {\_a}^{3} \left (-2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) \left (-2 \textit {\_a}^{3}+\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}}}}d \textit {\_a} \right )-x -c_2 &= 0 \\
\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {\left (1-i \sqrt {3}\right ) \textit {\_a}^{3} \left (-2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) \left (-2 \textit {\_a}^{3}+\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}}}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {\textit {\_a}^{3} {\left (\left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}-2 \textit {\_a} \right ) \textit {\_a}^{2}\right )}^{{1}/{3}} \left (\sqrt {3}+i\right ) \left (\left (\textit {\_a} c_1 \right )^{{1}/{4}}+2 i \textit {\_a} \right )}}d \textit {\_a} \right )-x -c_2 &= 0 \\
\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {\textit {\_a}^{3} {\left (\left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}-2 \textit {\_a} \right ) \textit {\_a}^{2}\right )}^{{1}/{3}} \left (\sqrt {3}+i\right ) \left (\left (\textit {\_a} c_1 \right )^{{1}/{4}}+2 i \textit {\_a} \right )}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {\textit {\_a}^{3} \left (2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) \left (-2 \textit {\_a}^{3}-\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}} \left (i \sqrt {3}-1\right )}}d \textit {\_a} \right )-x -c_2 &= 0 \\
\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {\textit {\_a}^{3} \left (2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) \left (-2 \textit {\_a}^{3}-\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}} \left (i \sqrt {3}-1\right )}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {\textit {\_a}^{3} \left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}+2 \textit {\_a} \right ) {\left (-\left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}+2 \textit {\_a} \right ) \textit {\_a}^{2}\right )}^{{1}/{3}} \left (i \sqrt {3}-1\right )}}d \textit {\_a} \right )-x -c_2 &= 0 \\
\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {\textit {\_a}^{3} \left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}+2 \textit {\_a} \right ) {\left (-\left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}+2 \textit {\_a} \right ) \textit {\_a}^{2}\right )}^{{1}/{3}} \left (i \sqrt {3}-1\right )}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {\left (-2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) \left (1+i \sqrt {3}\right ) \textit {\_a}^{3} \left (-2 \textit {\_a}^{3}+\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}}}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {\left (i-\sqrt {3}\right ) \textit {\_a}^{3} {\left (\left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}-2 \textit {\_a} \right ) \textit {\_a}^{2}\right )}^{{1}/{3}} \left (\left (\textit {\_a} c_1 \right )^{{1}/{4}}+2 i \textit {\_a} \right )}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {-2 \left (\textit {\_a} +\frac {\left (\textit {\_a} c_1 \right )^{{1}/{4}}}{2}\right ) \left (-2 \textit {\_a}^{3}-\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}} \left (1+i \sqrt {3}\right ) \textit {\_a}^{3}}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}^{2}}{\sqrt {-\textit {\_a}^{3} \left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}+2 \textit {\_a} \right ) {\left (-\left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}+2 \textit {\_a} \right ) \textit {\_a}^{2}\right )}^{{1}/{3}} \left (1+i \sqrt {3}\right )}}d \textit {\_a} \right )-x -c_2 &= 0 \\
\int _{}^{y}\frac {1}{\operatorname {RootOf}\left (-\ln \left (\textit {\_a} \right )-2 \left (\int _{}^{\textit {\_Z}}\frac {\textit {\_f}}{2 i \left (-\textit {\_f}^{2}\right )^{{1}/{4}}+\textit {\_f}^{2}}d \textit {\_f} \right )+c_1 \right ) \sqrt {\textit {\_a}}}d \textit {\_a} -x -c_2 &= 0 \\
\int _{}^{y}\frac {\textit {\_a}}{\sqrt {\textit {\_a} \left (-2 i \textit {\_a}^{3}-\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}} \left (\left (\textit {\_a} c_1 \right )^{{1}/{4}}+2 i \textit {\_a} \right )}}d \textit {\_a} -x -c_2 &= 0 \\
\int _{}^{y}\frac {\textit {\_a}}{\sqrt {\textit {\_a} \left (-2 i \textit {\_a}^{3}+\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}} \left (2 i \textit {\_a} -\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )}}d \textit {\_a} -x -c_2 &= 0 \\
\int _{}^{y}\frac {\textit {\_a}}{\sqrt {-i \textit {\_a} {\left (i \left (-2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) \textit {\_a}^{2}\right )}^{{1}/{3}} \left (-2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )}}d \textit {\_a} -x -c_2 &= 0 \\
\int _{}^{y}\frac {\textit {\_a}}{\sqrt {i \textit {\_a} {\left (-i \left (2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) \textit {\_a}^{2}\right )}^{{1}/{3}} \left (2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )}}d \textit {\_a} -x -c_2 &= 0 \\
\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}}{\sqrt {\left (i-\sqrt {3}\right ) \left (-2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) {\left (i \left (-2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) \textit {\_a}^{2}\right )}^{{1}/{3}} \textit {\_a}}}d \textit {\_a} \right )-x -c_2 &= 0 \\
\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}}{\sqrt {\left (\sqrt {3}+i\right ) \left (-2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) {\left (i \left (-2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) \textit {\_a}^{2}\right )}^{{1}/{3}} \textit {\_a}}}d \textit {\_a} \right )-x -c_2 &= 0 \\
\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}}{\sqrt {\left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}-2 \textit {\_a} \right ) \left (-2 i \textit {\_a}^{3}-\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}} \textit {\_a} \left (\sqrt {3}+i\right )}}d \textit {\_a} \right )-x -c_2 &= 0 \\
\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}}{\sqrt {\left (-2 i \textit {\_a}^{3}+\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}} \textit {\_a} \left (-i+\sqrt {3}\right ) \left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}+2 \textit {\_a} \right )}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\left (\int _{}^{y}\frac {\textit {\_a}}{\sqrt {\textit {\_a} \left (-2 i \textit {\_a}^{3}-\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}} \left (\left (\textit {\_a} c_1 \right )^{{1}/{4}}+2 i \textit {\_a} \right )}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\left (\int _{}^{y}\frac {\textit {\_a}}{\sqrt {\textit {\_a} \left (-2 i \textit {\_a}^{3}+\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}} \left (2 i \textit {\_a} -\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\left (\int _{}^{y}\frac {\textit {\_a}}{\sqrt {-i \textit {\_a} {\left (i \left (-2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) \textit {\_a}^{2}\right )}^{{1}/{3}} \left (-2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\left (\int _{}^{y}\frac {\textit {\_a}}{\sqrt {i \textit {\_a} {\left (-i \left (2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) \textit {\_a}^{2}\right )}^{{1}/{3}} \left (2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}}{\sqrt {\left (-i+\sqrt {3}\right ) \left (2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) {\left (-i \left (2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) \textit {\_a}^{2}\right )}^{{1}/{3}} \textit {\_a}}}d \textit {\_a} \right )-x -c_2 &= 0 \\
\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}}{\sqrt {\left (-i+\sqrt {3}\right ) \left (2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) {\left (-i \left (2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) \textit {\_a}^{2}\right )}^{{1}/{3}} \textit {\_a}}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}}{\sqrt {-\left (\sqrt {3}+i\right ) \left (2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) {\left (-i \left (2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) \textit {\_a}^{2}\right )}^{{1}/{3}} \textit {\_a}}}d \textit {\_a} \right )-x -c_2 &= 0 \\
\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}}{\sqrt {-\left (\sqrt {3}+i\right ) \left (2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) {\left (-i \left (2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) \textit {\_a}^{2}\right )}^{{1}/{3}} \textit {\_a}}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}}{\sqrt {\left (i-\sqrt {3}\right ) \left (-2 i \textit {\_a}^{3}-\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}} \left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}-2 \textit {\_a} \right ) \textit {\_a}}}d \textit {\_a} \right )-x -c_2 &= 0 \\
\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}}{\sqrt {\left (i-\sqrt {3}\right ) \left (-2 i \textit {\_a}^{3}-\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}} \left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}-2 \textit {\_a} \right ) \textit {\_a}}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}}{\sqrt {-\left (-2 i \textit {\_a}^{3}+\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}} \left (\sqrt {3}+i\right ) \left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}+2 \textit {\_a} \right ) \textit {\_a}}}d \textit {\_a} \right )-x -c_2 &= 0 \\
\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}}{\sqrt {-\left (-2 i \textit {\_a}^{3}+\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}} \left (\sqrt {3}+i\right ) \left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}+2 \textit {\_a} \right ) \textit {\_a}}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}}{\sqrt {\left (i-\sqrt {3}\right ) \left (-2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) {\left (i \left (-2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) \textit {\_a}^{2}\right )}^{{1}/{3}} \textit {\_a}}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}}{\sqrt {\left (\sqrt {3}+i\right ) \left (-2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) {\left (i \left (-2 \textit {\_a} +\left (\textit {\_a} c_1 \right )^{{1}/{4}}\right ) \textit {\_a}^{2}\right )}^{{1}/{3}} \textit {\_a}}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}}{\sqrt {\left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}-2 \textit {\_a} \right ) \left (-2 i \textit {\_a}^{3}-\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}} \textit {\_a} \left (\sqrt {3}+i\right )}}d \textit {\_a} \right )-x -c_2 &= 0 \\
-\sqrt {2}\, \left (\int _{}^{y}\frac {\textit {\_a}}{\sqrt {\left (-2 i \textit {\_a}^{3}+\textit {\_a}^{2} \left (\textit {\_a} c_1 \right )^{{1}/{4}}\right )^{{1}/{3}} \textit {\_a} \left (-i+\sqrt {3}\right ) \left (i \left (\textit {\_a} c_1 \right )^{{1}/{4}}+2 \textit {\_a} \right )}}d \textit {\_a} \right )-x -c_2 &= 0 \\
\int _{}^{y}\frac {1}{\operatorname {RootOf}\left (-\ln \left (\textit {\_a} \right )-2 \left (\int _{}^{\textit {\_Z}}\frac {\textit {\_f}}{\textit {\_f}^{2}+2 \left (-\textit {\_f}^{2}\right )^{{1}/{4}}}d \textit {\_f} \right )+c_1 \right ) \sqrt {\textit {\_a}}}d \textit {\_a} -x -c_2 &= 0 \\
\end{align*}
1.48.5 Mathematica DSolve solution
Solving time : 6.004
(sec)
Leaf size : 1237
DSolve[{y[x]*D[y[x],{x,2}]^4+D[y[x],x]^2==0,{}},
y[x],x,IncludeSingularSolutions->True]
Too large to display