20.3 problem 2 part 2

Internal problem ID [809]

Book: Elementary differential equations and boundary value problems, 10th ed., Boyce and DiPrima
Section: Chapter 9.2, Autonomous Systems and Stability. page 517
Problem number: 2 part 2.
ODE order: 1.
ODE degree: 1.

Solve \begin {align*} x^{\prime }\left (t \right )&=-x \left (t \right )\\ y^{\prime }\left (t \right )&=2 y \left (t \right ) \end {align*}

With initial conditions \[ [x \left (0\right ) = 4, y \left (0\right ) = 0] \]

Solution by Maple

Time used: 0.0 (sec). Leaf size: 15

dsolve([diff(x(t),t) = -x(t), diff(y(t),t) = 2*y(t), x(0) = 4, y(0) = 0], singsol=all)
 

\begin{align*} x \left (t \right ) &= 4 \,{\mathrm e}^{-t} \\ y \left (t \right ) &= 0 \\ \end{align*}

Solution by Mathematica

Time used: 0.042 (sec). Leaf size: 16

DSolve[{x'[t]==-1*x[t]+0*y[t],y'[t]==0*x[t]+2*y[t]},{x[0]==4,y[0]==0},{x[t],y[t]},t,IncludeSingularSolutions -> True]
 

\begin{align*} x(t)\to 4 e^{-t} \\ y(t)\to 0 \\ \end{align*}