Internal problem ID [12181]
Book: DIFFERENTIAL and INTEGRAL CALCULUS. VOL I. by N. PISKUNOV. MIR
PUBLISHERS, Moscow 1969.
Section: Chapter 8. Differential equations. Exercises page 595
Problem number: 129.
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(x),x$2)=9*y(x),y(x), singsol=all)
\[ y \left (x \right ) = c_{1} {\mathrm e}^{-3 x}+c_{2} {\mathrm e}^{3 x} \]
✓ Solution by Mathematica
Time used: 0.023 (sec). Leaf size: 22
DSolve[y''[x]==9*y[x],y[x],x,IncludeSingularSolutions -> True]
\[ y(x)\to e^{-3 x} \left (c_1 e^{6 x}+c_2\right ) \]