1.334 problem 335

Internal problem ID [7915]

Book: Differential Gleichungen, E. Kamke, 3rd ed. Chelsea Pub. NY, 1948
Section: Chapter 1, linear first order
Problem number: 335.
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [_separable]

Solve \begin {gather*} \boxed {\sqrt {y^{2}-1}\, y^{\prime }-\sqrt {x^{2}-1}=0} \end {gather*}

Solution by Maple

Time used: 0.0 (sec). Leaf size: 50

dsolve((y(x)^2-1)^(1/2)*diff(y(x),x)-(x^2-1)^(1/2) = 0,y(x), singsol=all)
 

\[ c_{1}+\sqrt {x^{2}-1}\, x -\ln \left (x +\sqrt {x^{2}-1}\right )-y \relax (x ) \sqrt {-1+y \relax (x )^{2}}+\ln \left (y \relax (x )+\sqrt {-1+y \relax (x )^{2}}\right ) = 0 \]

Solution by Mathematica

Time used: 0.599 (sec). Leaf size: 77

DSolve[-Sqrt[-1 + x^2] + Sqrt[-1 + y[x]^2]*y'[x]==0,y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} y(x)\to \text {InverseFunction}\left [\frac {1}{2} \text {$\#$1} \sqrt {\text {$\#$1}^2-1}-\tanh ^{-1}\left (\frac {\sqrt {\text {$\#$1}^2-1}}{\text {$\#$1}-1}\right )\&\right ]\left [\frac {1}{2} \sqrt {x^2-1} x+\coth ^{-1}\left (\frac {1-x}{\sqrt {x^2-1}}\right )+c_1\right ] \\ \end{align*}