64.10.11 problem 11

Internal problem ID [13417]
Book : Differential Equations by Shepley L. Ross. Third edition. John Willey. New Delhi. 2004.
Section : Chapter 4, Section 4.2. The homogeneous linear equation with constant coefficients. Exercises page 135
Problem number : 11
Date solved : Tuesday, January 28, 2025 at 05:42:07 AM
CAS classification : [[_2nd_order, _missing_x]]

\begin{align*} y^{\prime \prime }+9 y&=0 \end{align*}

✓ Solution by Maple

Time used: 0.001 (sec). Leaf size: 17

dsolve(diff(y(x),x$2)+9*y(x)=0,y(x), singsol=all)
 

\[ y = c_{1} \sin \left (3 x \right )+c_{2} \cos \left (3 x \right ) \]

✓ Solution by Mathematica

Time used: 0.012 (sec). Leaf size: 20

DSolve[D[y[x],{x,2}]+9*y[x]==0,y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to c_1 \cos (3 x)+c_2 \sin (3 x) \]