14.29 problem 31

Internal problem ID [2230]

Book: Differential Equations by Alfred L. Nelson, Karl W. Folley, Max Coral. 3rd ed. DC heath. Boston. 1964
Section: Exercise 23, page 106
Problem number: 31.
ODE order: 3.
ODE degree: 1.

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

\[ \boxed {y^{\prime \prime \prime }+4 y^{\prime \prime }+5 y^{\prime }={\mathrm e}^{-2 x} \cos \left (x \right )} \]

Solution by Maple

Time used: 0.016 (sec). Leaf size: 40

dsolve(diff(y(x),x$3)+4*diff(y(x),x$2)+5*diff(y(x),x)=exp(-2*x)*cos(x),y(x), singsol=all)
 

\[ y \left (x \right ) = \frac {\left (\left (-5 x -20 c_{1} -10 c_{2} -4\right ) \cos \left (x \right )-10 \sin \left (x \right ) \left (x -c_{1} +2 c_{2} +\frac {3}{10}\right )\right ) {\mathrm e}^{-2 x}}{50}+c_{3} \]

Solution by Mathematica

Time used: 0.337 (sec). Leaf size: 52

DSolve[y'''[x]+4*y''[x]+5*y'[x]==Exp[-2*x]*Cos[x],y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to \frac {1}{50} e^{-2 x} (2 (-5 x+1-10 c_1+5 c_2) \sin (x)-(5 x+14+10 c_1+20 c_2) \cos (x))+c_3 \]