15.7 problem 8

Internal problem ID [2240]

Book: Differential Equations by Alfred L. Nelson, Karl W. Folley, Max Coral. 3rd ed. DC heath. Boston. 1964
Section: Exercise 24, page 109
Problem number: 8.
ODE order: 3.
ODE degree: 1.

CAS Maple gives this as type [[_3rd_order, _missing_y]]

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

Solution by Maple

Time used: 0.0 (sec). Leaf size: 25

dsolve(diff(y(x),x$3)+diff(y(x),x)=sin(x),y(x), singsol=all)
 

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

Solution by Mathematica

Time used: 0.074 (sec). Leaf size: 31

DSolve[y'''[x]+y'[x]==Sin[x],y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to -\frac {1}{2} (1+2 c_2) \cos (x)+\left (-\frac {x}{2}+c_1\right ) \sin (x)+c_3 \]