4.3 problem 9.1 (iii)

Internal problem ID [10649]

Book: AN INTRODUCTION TO ORDINARY DIFFERENTIAL EQUATIONS by JAMES C. ROBINSON. Cambridge University Press 2004
Section: Chapter 9, First order linear equations and the integrating factor. Exercises page 86
Problem number: 9.1 (iii).
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [_linear]

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

Solution by Maple

Time used: 0.015 (sec). Leaf size: 17

dsolve(diff(z(y),y)=z(y)*tan(y)+sin(y),z(y), singsol=all)
 

\[ z \left (y \right ) = \frac {-\frac {\cos \left (2 y \right )}{4}+c_{1}}{\cos \left (y \right )} \]

Solution by Mathematica

Time used: 0.046 (sec). Leaf size: 17

DSolve[z'[y]==z[y]*Tan[y]+Sin[y],z[y],y,IncludeSingularSolutions -> True]
 

\begin{align*} z(y)\to -\frac {\cos (y)}{2}+c_1 \sec (y) \\ \end{align*}