36.3.11 problem 12

Internal problem ID [6332]
Book : Fundamentals of Differential Equations. By Nagle, Saff and Snider. 9th edition. Boston. Pearson 2018.
Section : Chapter 2, First order differential equations. Section 2.4, Exact equations. Exercises. page 64
Problem number : 12
Date solved : Monday, January 27, 2025 at 01:56:43 PM
CAS classification : [_exact]

\begin{align*} \cos \left (x \right ) \cos \left (y\right )+2 x -\left (\sin \left (x \right ) \sin \left (y\right )+2 y\right ) y^{\prime }&=0 \end{align*}

✓ Solution by Maple

Time used: 0.017 (sec). Leaf size: 20

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

\[ \sin \left (x \right ) \cos \left (y\right )+x^{2}-y^{2}+c_1 = 0 \]

✓ Solution by Mathematica

Time used: 0.275 (sec). Leaf size: 25

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

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