1.1 problem Problem 1

Internal problem ID [12112]

Book: Differential equations and the calculus of variations by L. ElSGOLTS. MIR PUBLISHERS, MOSCOW, Third printing 1977.
Section: Chapter 1, First-Order Differential Equations. Problems page 88
Problem number: Problem 1.
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [_separable]

\[ \boxed {\tan \left (y\right )-y^{\prime } \cot \left (x \right )=0} \]

Solution by Maple

Time used: 0.203 (sec). Leaf size: 9

dsolve(tan(y(x))-cot(x)*diff(y(x),x)=0,y(x), singsol=all)
 

\[ y \left (x \right ) = \arcsin \left (\sec \left (x \right ) c_{1} \right ) \]

Solution by Mathematica

Time used: 4.745 (sec). Leaf size: 19

DSolve[Tan[y[x]]-Cot[x]*y'[x]==0,y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} y(x)\to \arcsin \left (\frac {1}{2} c_1 \sec (x)\right ) \\ y(x)\to 0 \\ \end{align*}