Internal problem ID [11648]
Book: Differential Equations by Shepley L. Ross. Third edition. John Willey. New Delhi.
2004.
Section: Chapter 2, section 2.3 (Linear equations). Exercises page 56
Problem number: 11.
ODE order: 1.
ODE degree: 1.
CAS Maple gives this as type [_linear]
\[ \boxed {r^{\prime }+r \tan \left (t \right )=\cos \left (t \right )} \]
✓ Solution by Maple
Time used: 0.0 (sec). Leaf size: 10
dsolve(diff(r(t),t)+r(t)*tan(t)=cos(t),r(t), singsol=all)
\[ r \left (t \right ) = \left (t +c_{1} \right ) \cos \left (t \right ) \]
✓ Solution by Mathematica
Time used: 0.06 (sec). Leaf size: 12
DSolve[r'[t]+r[t]*Tan[t]==Cos[t],r[t],t,IncludeSingularSolutions -> True]
\[ r(t)\to (t+c_1) \cos (t) \]