82.33.12 problem Ex. 12

Internal problem ID [18905]
Book : Introductory Course On Differential Equations by Daniel A Murray. Longmans Green and Co. NY. 1924
Section : Chapter VI. Linear equations with constant coefficients. Examples on chapter VI, page 80
Problem number : Ex. 12
Date solved : Tuesday, January 28, 2025 at 12:34:05 PM
CAS classification : [[_2nd_order, _linear, _nonhomogeneous]]

\begin{align*} y^{\prime \prime }+a^{2} y&=\sec \left (a x \right ) \end{align*}

Solution by Maple

Time used: 0.007 (sec). Leaf size: 40

dsolve(diff(y(x),x$2)+a^2*y(x)=sec(a*x),y(x), singsol=all)
 
\[ y \left (x \right ) = \sin \left (a x \right ) c_{2} +\cos \left (a x \right ) c_{1} +\frac {x \sin \left (a x \right ) a -\ln \left (\sec \left (a x \right )\right ) \cos \left (a x \right )}{a^{2}} \]

Solution by Mathematica

Time used: 0.035 (sec). Leaf size: 39

DSolve[D[y[x],{x,2}]+a^2*y[x]==Sec[a*x],y[x],x,IncludeSingularSolutions -> True]
 
\[ y(x)\to \frac {\cos (a x) \left (\log (\cos (a x))+a^2 c_1\right )+a (x+a c_2) \sin (a x)}{a^2} \]