Internal problem ID [12670]
Book: DIFFERENTIAL EQUATIONS by Paul Blanchard, Robert L. Devaney, Glen R. Hall. 4th
edition. Brooks/Cole. Boston, USA. 2012
Section: Chapter 1. First-Order Differential Equations. Exercises section 1.8 page 121
Problem number: 1.
ODE order: 1.
ODE degree: 1.
CAS Maple gives this as type [[_linear, `class A`]]
\[ \boxed {y^{\prime }+4 y=9 \,{\mathrm e}^{-t}} \]
✓ Solution by Maple
Time used: 0.0 (sec). Leaf size: 17
dsolve(diff(y(t),t)=-4*y(t)+9*exp(-t),y(t), singsol=all)
\[ y \left (t \right ) = \left (3 \,{\mathrm e}^{3 t}+c_{1} \right ) {\mathrm e}^{-4 t} \]
✓ Solution by Mathematica
Time used: 0.088 (sec). Leaf size: 21
DSolve[y'[t]==-4*y[t]+9*Exp[-t],y[t],t,IncludeSingularSolutions -> True]
\[ y(t)\to e^{-4 t} \left (3 e^{3 t}+c_1\right ) \]