3.1 problem 8

Internal problem ID [833]

Book: Elementary differential equations and boundary value problems, 11th ed., Boyce, DiPrima, Meade
Section: Chapter 6.2, The Laplace Transform. Solution of Initial Value Problems. page 255
Problem number: 8.
ODE order: 2.
ODE degree: 1.

CAS Maple gives this as type [[_2nd_order, _missing_x]]

Solve \begin {gather*} \boxed {y^{\prime \prime }-y^{\prime }-6 y=0} \end {gather*} With initial conditions \begin {align*} [y \relax (0) = 1, y^{\prime }\relax (0) = -1] \end {align*}

Solution by Maple

Time used: 0.015 (sec). Leaf size: 16

dsolve([diff(y(t),t$2)-diff(y(t),t)-6*y(t)=0,y(0) = 1, D(y)(0) = -1],y(t), singsol=all)
 

\[ y \relax (t ) = \frac {\left ({\mathrm e}^{5 t}+4\right ) {\mathrm e}^{-2 t}}{5} \]

Solution by Mathematica

Time used: 0.003 (sec). Leaf size: 21

DSolve[{y''[t]-y'[t]-6*y[t]==0,{y[0]==1,y'[0]==-1}},y[t],t,IncludeSingularSolutions -> True]
 

\begin{align*} y(t)\to \frac {1}{5} e^{-2 t} \left (e^{5 t}+4\right ) \\ \end{align*}