2.20 problem 40

2.20.1 Solving as quadrature ode
2.20.2 Maple step by step solution

Internal problem ID [14966]
Internal file name [OUTPUT/14976_Monday_April_15_2024_12_04_33_AM_92472098/index.tex]

Book: A book of problems in ordinary differential equations. M.L. KRASNOV, A.L. KISELYOV, G.I. MARKARENKO. MIR, MOSCOW. 1983
Section: Section 2. The method of isoclines. Exercises page 27
Problem number: 40.
ODE order: 1.
ODE degree: 1.

The type(s) of ODE detected by this program : "quadrature"

Maple gives the following as the ode type

[_quadrature]

\[ \boxed {y^{\prime }-y^{2}=0} \]

2.20.1 Solving as quadrature ode

Integrating both sides gives \begin {align*} \int \frac {1}{y^{2}}d y &= x +c_{1}\\ -\frac {1}{y}&=x +c_{1} \end {align*}

Solving for \(y\) gives these solutions \begin {align*} y_1&=-\frac {1}{x +c_{1}} \end {align*}

Summary

The solution(s) found are the following \begin{align*} \tag{1} y &= -\frac {1}{x +c_{1}} \\ \end{align*}

Figure 74: Slope field plot

Verification of solutions

\[ y = -\frac {1}{x +c_{1}} \] Verified OK.

2.20.2 Maple step by step solution

\[ \begin {array}{lll} & {} & \textrm {Let's solve}\hspace {3pt} \\ {} & {} & y^{\prime }-y^{2}=0 \\ \bullet & {} & \textrm {Highest derivative means the order of the ODE is}\hspace {3pt} 1 \\ {} & {} & y^{\prime } \\ \bullet & {} & \textrm {Solve for the highest derivative}\hspace {3pt} \\ {} & {} & y^{\prime }=y^{2} \\ \bullet & {} & \textrm {Separate variables}\hspace {3pt} \\ {} & {} & \frac {y^{\prime }}{y^{2}}=1 \\ \bullet & {} & \textrm {Integrate both sides with respect to}\hspace {3pt} x \\ {} & {} & \int \frac {y^{\prime }}{y^{2}}d x =\int 1d x +c_{1} \\ \bullet & {} & \textrm {Evaluate integral}\hspace {3pt} \\ {} & {} & -\frac {1}{y}=x +c_{1} \\ \bullet & {} & \textrm {Solve for}\hspace {3pt} y \\ {} & {} & y=-\frac {1}{x +c_{1}} \end {array} \]

Maple trace

`Methods for first order ODEs: 
--- Trying classification methods --- 
trying a quadrature 
trying 1st order linear 
trying Bernoulli 
<- Bernoulli successful`
 

Solution by Maple

Time used: 0.0 (sec). Leaf size: 11

dsolve(diff(y(x),x)=y(x)^2,y(x), singsol=all)
 

\[ y \left (x \right ) = \frac {1}{c_{1} -x} \]

Solution by Mathematica

Time used: 0.088 (sec). Leaf size: 18

DSolve[y'[x]==y[x]^2,y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} y(x)\to -\frac {1}{x+c_1} \\ y(x)\to 0 \\ \end{align*}