6.4 problem 12.1 (iv)

Internal problem ID [11697]

Book: AN INTRODUCTION TO ORDINARY DIFFERENTIAL EQUATIONS by JAMES C. ROBINSON. Cambridge University Press 2004
Section: Chapter 12, Homogeneous second order linear equations. Exercises page 118
Problem number: 12.1 (iv).
ODE order: 2.
ODE degree: 1.

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

\[ \boxed {y^{\prime \prime }+y^{\prime }-6 y=0} \] With initial conditions \begin {align*} [y \left (0\right ) = -1, y^{\prime }\left (0\right ) = 8] \end {align*}

Solution by Maple

Time used: 0.015 (sec). Leaf size: 15

dsolve([diff(y(t),t$2)+diff(y(t),t)-6*y(t)=0,y(0) = -1, D(y)(0) = 8],y(t), singsol=all)
 

\[ y \left (t \right ) = \left ({\mathrm e}^{5 t}-2\right ) {\mathrm e}^{-3 t} \]

Solution by Mathematica

Time used: 0.023 (sec). Leaf size: 18

DSolve[{y''[t]+y'[t]-6*y[t]==0,{y[0]==-1,y'[0]==8}},y[t],t,IncludeSingularSolutions -> True]
 

\[ y(t)\to e^{-3 t} \left (e^{5 t}-2\right ) \]