25.3 problem Ex 3

Internal problem ID [10241]

Book: An elementary treatise on differential equations by Abraham Cohen. DC heath publishers. 1906
Section: Chapter VII, Linear differential equations with constant coefficients. Article 48. Page 103
Problem number: Ex 3.
ODE order: 2.
ODE degree: 1.

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

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

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)
 

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

Solution by Mathematica

Time used: 0.008 (sec). Leaf size: 22

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

\begin{align*} y(x)\to (x+c_2) \sin (x)+\cos (x) (\log (\cos (x))+c_1) \\ \end{align*}