1.189 problem 190

Internal problem ID [7770]

Book: Differential Gleichungen, E. Kamke, 3rd ed. Chelsea Pub. NY, 1948
Section: Chapter 1, linear first order
Problem number: 190.
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [_separable]

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

Solution by Maple

Time used: 0.001 (sec). Leaf size: 29

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

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

Solution by Mathematica

Time used: 1.429 (sec). Leaf size: 130

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

\begin{align*} y(x)\to -\frac {e^{-c_1} \sqrt {e^{2 c_1} \left (\left (2 x^2-1\right ) \cosh (2 c_1)+2 x \sqrt {x^2-1} \sinh (2 c_1)+1\right )}}{\sqrt {2}} \\ y(x)\to \frac {e^{-c_1} \sqrt {e^{2 c_1} \left (\left (2 x^2-1\right ) \cosh (2 c_1)+2 x \sqrt {x^2-1} \sinh (2 c_1)+1\right )}}{\sqrt {2}} \\ y(x)\to -1 \\ y(x)\to 1 \\ \end{align*}