4.4   ODE No. 1004

$$\boxed{{\displaystyle \frac{{\mathrm{d}}^2}{\mathrm{d}{x}^2}y\left(x\right)+y\left(x\right)-a\cos \left(bx\right)=0}}$$

1. Problem in Latex
2. Mathematica input
3. Maple input

Mathematica: cpu = 0.097012 (sec), leaf count = 47 $$\left\{\{y(x)\to \frac{-a{\cos }^2(x)\cos (bx)-a{\sin }^2(x)\cos (bx)}{b^2-1}+c_2\sin (x)+c_1\cos (x)\}\right\}$$

Maple: cpu = 0.031 (sec), leaf count = 27 $$\{y\left(x\right)=\sin \left(x\right)\mathit{\_}\mathit{C}\mathit{2}+\cos \left(x\right)\mathit{\_}\mathit{C}\mathit{1}-\frac{a\cos \left(bx\right)}{b^2-1}\}$$