1.4 problem 4

Internal problem ID [4963]

Book: Ordinary differential equations and calculus of variations. Makarets and Reshetnyak. Wold Scientific. Singapore. 1995
Section: Chapter 1. First order differential equations. Section 1.1 Separable equations problems. page 7
Problem number: 4.
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [_separable]

\[ \boxed {y^{\prime } x -\sqrt {1-y^{2}}=0} \]

Solution by Maple

Time used: 0.0 (sec). Leaf size: 9

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

\[ y \left (x \right ) = \sin \left (\ln \left (x \right )+c_{1} \right ) \]

Solution by Mathematica

Time used: 0.266 (sec). Leaf size: 29

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

\begin{align*} y(x)\to \cos (\log (x)+c_1) \\ y(x)\to -1 \\ y(x)\to 1 \\ y(x)\to \text {Interval}[\{-1,1\}] \\ \end{align*}