77.1.6 problem 17 (page 27)

Internal problem ID [17825]
Book : V.V. Stepanov, A course of differential equations (in Russian), GIFML. Moscow (1958)
Section : All content
Problem number : 17 (page 27)
Date solved : Monday, March 31, 2025 at 04:34:09 PM
CAS classification : [_separable]

\begin{align*} \sqrt {-x^{2}+1}\, y^{\prime }+\sqrt {1-y^{2}}&=0 \end{align*}

✓ Maple. Time used: 0.004 (sec). Leaf size: 11

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

\[ y = -\sin \left (\arcsin \left (x \right )+c_1 \right ) \]

✓ Mathematica. Time used: 0.189 (sec). Leaf size: 33

ode=Sqrt[1-x^2]*D[y[x],x]+Sqrt[1-y[x]^2]==0; 
ic={}; 
DSolve[{ode,ic},y[x],x,IncludeSingularSolutions->True]
 

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

✓ Sympy. Time used: 0.286 (sec). Leaf size: 8

from sympy import * 
x = symbols("x") 
y = Function("y") 
ode = Eq(sqrt(1 - x**2)*Derivative(y(x), x) + sqrt(1 - y(x)**2),0) 
ics = {} 
dsolve(ode,func=y(x),ics=ics)
 

\[ y{\left (x \right )} = \sin {\left (C_{1} - \operatorname {asin}{\left (x \right )} \right )} \]