15.9.18 problem 32

Internal problem ID [3075]
Book : Differential Equations by Alfred L. Nelson, Karl W. Folley, Max Coral. 3rd ed. DC heath. Boston. 1964
Section : Exercise 17, page 78
Problem number : 32
Date solved : Monday, January 27, 2025 at 07:19:12 AM
CAS classification : [[_3rd_order, _missing_x]]

\begin{align*} y^{\prime \prime \prime }-9 y^{\prime \prime }+23 y^{\prime }-15 y&=0 \end{align*}

✓ Solution by Maple

Time used: 0.004 (sec). Leaf size: 21

dsolve(diff(y(x),x$3)-9*diff(y(x),x$2)+23*diff(y(x),x)-15*y(x)=0,y(x), singsol=all)
 

\[ y = {\mathrm e}^{5 x} c_{1} +c_2 \,{\mathrm e}^{3 x}+c_3 \,{\mathrm e}^{x} \]

✓ Solution by Mathematica

Time used: 0.004 (sec). Leaf size: 28

DSolve[D[y[x],{x,3}]-9*D[y[x],{x,2}]+23*D[y[x],x]-15*y[x]==0,y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to e^x \left (c_2 e^{2 x}+c_3 e^{4 x}+c_1\right ) \]