1.18 problem 18

Internal problem ID [2560]

Book: Advanced Mathematica, Book2, Perkin and Perkin, 1992
Section: Chapter 11.3, page 316
Problem number: 18.
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [_separable]

Solve \begin {gather*} \boxed {x \cos \relax (y) y^{\prime }-1-\sin \relax (y)=0} \end {gather*} With initial conditions \begin {align*} [y \relax (1) = 0] \end {align*}

Solution by Maple

Time used: 0.156 (sec). Leaf size: 8

dsolve([x*cos(y(x))*diff(y(x),x)=1+sin(y(x)),y(1) = 0],y(x), singsol=all)
 

\[ y \relax (x ) = \arcsin \left (x -1\right ) \]

Solution by Mathematica

Time used: 60.244 (sec). Leaf size: 53

DSolve[{x*Cos[y[x]]*y'[x]==1+Sin[y[x]],y[1]==0},y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} y(x)\to -2 \text {ArcCos}\left (\frac {1}{2} \left (\sqrt {2-x}+\sqrt {x}\right )\right ) \\ y(x)\to 2 \text {ArcCos}\left (\frac {1}{2} \left (\sqrt {2-x}+\sqrt {x}\right )\right ) \\ \end{align*}