9.1 problem Exercise 22.1, page 240

Internal problem ID [4631]

Book: Ordinary Differential Equations, By Tenenbaum and Pollard. Dover, NY 1963
Section: Chapter 4. Higher order linear differential equations. Lesson 22. Variation of Parameters
Problem number: Exercise 22.1, page 240.
ODE order: 2.
ODE degree: 1.

CAS Maple gives this as type [[_2nd_order, _linear, _nonhomogeneous]]

\[ \boxed {y^{\prime \prime }+y=\sec \left (x \right )} \]

Solution by Maple

Time used: 0.0 (sec). Leaf size: 24

dsolve(diff(y(x),x$2)+y(x)=sec(x),y(x), singsol=all)
 

\[ y \left (x \right ) = c_{2} \sin \left (x \right )+c_{1} \cos \left (x \right )+x \sin \left (x \right )-\ln \left (\sec \left (x \right )\right ) \cos \left (x \right ) \]

Solution by Mathematica

Time used: 0.021 (sec). Leaf size: 22

DSolve[y''[x]+y[x]==Sec[x],y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to (x+c_2) \sin (x)+\cos (x) (\log (\cos (x))+c_1) \]