Internal problem ID [13556]
Book: Ordinary Differential Equations. An introduction to the fundamentals. Kenneth B. Howell.
second edition. CRC Press. FL, USA. 2020
Section: Chapter 14. Higher order equations and the reduction of order method. Additional
exercises page 277
Problem number: 14.5 (a).
ODE order: 3.
ODE degree: 1.
CAS Maple gives this as type [[_3rd_order, _missing_x]]
\[ \boxed {y^{\prime \prime \prime }-9 y^{\prime \prime }+27 y^{\prime }-27 y=0} \]
✓ Solution by Maple
Time used: 0.0 (sec). Leaf size: 19
dsolve([diff(y(x),x$3)-9*diff(y(x),x$2)+27*diff(y(x),x)-27*y(x)=0,exp(3*x)],singsol=all)
\[ y \left (x \right ) = {\mathrm e}^{3 x} \left (x^{2} c_{3} +c_{2} x +c_{1} \right ) \]
✓ Solution by Mathematica
Time used: 0.009 (sec). Leaf size: 23
DSolve[y'''[x]-9*y''[x]+27*y'[x]-27*y[x]==0,y[x],x,IncludeSingularSolutions -> True]
\[ y(x)\to e^{3 x} (x (c_3 x+c_2)+c_1) \]