11.22 problem 45

Internal problem ID [240]

Book: Differential equations and linear algebra, 3rd ed., Edwards and Penney
Section: Section 5.5, Nonhomogeneous equations and undetermined coefficients Page 351
Problem number: 45.
ODE order: 2.
ODE degree: 1.

CAS Maple gives this as type [[_2nd_order, _linear, _nonhomogeneous]]

\[ \boxed {y^{\prime \prime }+9 y=\sin \left (x \right )^{4}} \]

Solution by Maple

Time used: 0.0 (sec). Leaf size: 32

dsolve(diff(y(x),x$2)+9*y(x)=sin(x)^4,y(x), singsol=all)
 

\[ y \left (x \right ) = \sin \left (3 x \right ) c_{2} +\cos \left (3 x \right ) c_{1} -\frac {\cos \left (2 x \right )}{10}-\frac {\cos \left (2 x \right )^{2}}{28}+\frac {5}{84} \]

Solution by Mathematica

Time used: 0.215 (sec). Leaf size: 39

DSolve[y''[x]+9*y[x]==Sin[x]^4,y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to -\frac {1}{10} \cos (2 x)-\frac {1}{56} \cos (4 x)+c_1 \cos (3 x)+c_2 \sin (3 x)+\frac {1}{24} \]