83.46.1 problem Ex 1 page 68

Internal problem ID [19566]
Book : A Text book for differentional equations for postgraduate students by Ray and Chaturvedi. First edition, 1958. BHASKAR press. INDIA
Section : Book Solved Excercises. Chapter V. Singular solutions
Problem number : Ex 1 page 68
Date solved : Tuesday, January 28, 2025 at 01:57:04 PM
CAS classification : [_rational, [_1st_order, `_with_symmetry_[F(x),G(x)*y+H(x)]`]]

\begin{align*} {y^{\prime }}^{2} \left (-x^{2}+1\right )&=1-y^{2} \end{align*}

Solution by Maple

Time used: 0.075 (sec). Leaf size: 162

dsolve(diff(y(x),x)^2*(1-x^2)=1-y(x)^2,y(x), singsol=all)
 
\begin{align*} y \left (x \right ) &= -1 \\ y \left (x \right ) &= 1 \\ \frac {\sqrt {-1+y \left (x \right )^{2}}\, \ln \left (y \left (x \right )+\sqrt {-1+y \left (x \right )^{2}}\right )}{\sqrt {y \left (x \right )-1}\, \sqrt {y \left (x \right )+1}}-\frac {\int _{}^{x}\frac {\sqrt {\left (\textit {\_a}^{2}-1\right ) \left (-1+y \left (x \right )^{2}\right )}}{\textit {\_a}^{2}-1}d \textit {\_a}}{\sqrt {y \left (x \right )-1}\, \sqrt {y \left (x \right )+1}}+c_{1} &= 0 \\ \frac {\sqrt {-1+y \left (x \right )^{2}}\, \ln \left (y \left (x \right )+\sqrt {-1+y \left (x \right )^{2}}\right )}{\sqrt {y \left (x \right )-1}\, \sqrt {y \left (x \right )+1}}+\frac {\int _{}^{x}\frac {\sqrt {\left (\textit {\_a}^{2}-1\right ) \left (-1+y \left (x \right )^{2}\right )}}{\textit {\_a}^{2}-1}d \textit {\_a}}{\sqrt {y \left (x \right )-1}\, \sqrt {y \left (x \right )+1}}+c_{1} &= 0 \\ \end{align*}

Solution by Mathematica

Time used: 0.250 (sec). Leaf size: 98

DSolve[D[y[x],x]^2*(1-x^2)==1-y[x]^2,y[x],x,IncludeSingularSolutions -> True]
 
\begin{align*} y(x)\to \frac {1}{2} e^{-c_1} \left (\left (1+e^{2 c_1}\right ) x-\left (-1+e^{2 c_1}\right ) \sqrt {x^2-1}\right ) \\ y(x)\to \frac {1}{2} e^{-c_1} \left (\left (-1+e^{2 c_1}\right ) \sqrt {x^2-1}+\left (1+e^{2 c_1}\right ) x\right ) \\ y(x)\to -1 \\ y(x)\to 1 \\ \end{align*}