27.17 problem 38.10 (k)

Internal problem ID [14037]

Book: Ordinary Differential Equations. An introduction to the fundamentals. Kenneth B. Howell. second edition. CRC Press. FL, USA. 2020
Section: Chapter 38. Systems of differential equations. A starting point. Additional Exercises. page 786
Problem number: 38.10 (k).
ODE order: 1.
ODE degree: 1.

Solve \begin {align*} x^{\prime }\left (t \right )&=4 x \left (t \right )-13 y \left (t \right )\\ y^{\prime }\left (t \right )&=x \left (t \right )+152 \cos \left (t \right )^{4}-152 \cos \left (t \right )^{2}+19-104 \cos \left (t \right )^{3} \sin \left (t \right )+52 \cos \left (t \right ) \sin \left (t \right ) \end {align*}

With initial conditions \[ [x \left (0\right ) = 13, y \left (0\right ) = 0] \]

Solution by Maple

Time used: 0.282 (sec). Leaf size: 27

dsolve([diff(x(t),t) = 4*x(t)-13*y(t), diff(y(t),t) = x(t)+19*cos(4*t)-13*sin(4*t), x(0) = 13, y(0) = 0], singsol=all)
 

\begin{align*} x \left (t \right ) &= 13 \sin \left (4 t \right )+13 \cos \left (4 t \right ) \\ y \left (t \right ) &= 8 \sin \left (4 t \right ) \\ \end{align*}

Solution by Mathematica

Time used: 0.021 (sec). Leaf size: 25

DSolve[{x'[t]==4*x[t]-13*y[t],y'[t]==x[t]+19*Cos[4*t]-13*Sin[4*t]},{x[0]==13,y[0]==0},{x[t],y[t]},t,IncludeSingularSolutions -> True]
 

\begin{align*} x(t)\to 13 (\sin (4 t)+\cos (4 t)) \\ y(t)\to 8 \sin (4 t) \\ \end{align*}