Internal problem ID [14448]
Book: INTRODUCTORY DIFFERENTIAL EQUATIONS. Martha L. Abell, James P. Braselton.
Fourth edition 2014. ElScAe. 2014
Section: Chapter 4. Higher Order Equations. Exercises 4.1, page 141
Problem number: 12.
ODE order: 2.
ODE degree: 1.
CAS Maple gives this as type [[_2nd_order, _missing_x]]
\[ \boxed {y^{\prime \prime }+9 y=0} \]
✓ Solution by Maple
Time used: 0.0 (sec). Leaf size: 17
dsolve(diff(y(t),t$2)+9*y(t)=0,y(t), singsol=all)
\[ y \left (t \right ) = c_{1} \sin \left (3 t \right )+\cos \left (3 t \right ) c_{2} \]
✓ Solution by Mathematica
Time used: 0.014 (sec). Leaf size: 20
DSolve[y''[t]+9*y[t]==0,y[t],t,IncludeSingularSolutions -> True]
\[ y(t)\to c_1 \cos (3 t)+c_2 \sin (3 t) \]