4.6 problem 6

Internal problem ID [4272]

Book: Mathematical Methods in the Physical Sciences. third edition. Mary L. Boas. John Wiley. 2006
Section: Chapter 8, Ordinary differential equations. Section 4. OTHER METHODS FOR FIRST-ORDER EQUATIONS. page 406
Problem number: 6.
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type unknown

Solve \begin {gather*} \boxed {\cos \relax (x ) \cos \relax (y)+\sin ^{2}\relax (x )-\left (\sin \relax (x ) \sin \relax (y)+\cos ^{2}\relax (y)\right ) y^{\prime }=0} \end {gather*}

Solution by Maple

dsolve((cos(x)*cos(y(x))+sin(x)^2)-(sin(x)*sin(y(x))+cos(y(x))^2)*diff(y(x),x)=0,y(x), singsol=all)
 

\[ \text {No solution found} \]

Solution by Mathematica

Time used: 0.392 (sec). Leaf size: 43

DSolve[(Cos[x]*Cos[y[x]]+Sin[x]^2)-(Sin[x]*Sin[y[x]]+Cos[y[x]]^2)*y'[x]==0,y[x],x,IncludeSingularSolutions -> True]
 

\[ \text {Solve}\left [2 \left (\frac {y(x)}{2}+\frac {1}{4} \sin (2 y(x))\right )-2 \sin (x) \cos (y(x))-x+\frac {1}{2} \sin (2 x)=c_1,y(x)\right ] \]