12.18 problem 18

Internal problem ID [2191]

Book: Differential Equations by Alfred L. Nelson, Karl W. Folley, Max Coral. 3rd ed. DC heath. Boston. 1964
Section: Exercise 20, page 90
Problem number: 18.
ODE order: 2.
ODE degree: 1.

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

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

Solution by Maple

Time used: 0.0 (sec). Leaf size: 36

dsolve(diff(y(x),x$2)+4*y(x)=sec(x)*tan(x),y(x), singsol=all)
 

\[ y = c_{2} \sin \left (2 x \right )+\cos \left (2 x \right ) c_{1} +\left (1-2 \cos \left (x \right )^{2}\right ) \ln \left (\sec \left (x \right )+\tan \left (x \right )\right )-2 \sin \left (x \right ) \]

Solution by Mathematica

Time used: 0.081 (sec). Leaf size: 33

DSolve[y''[x]+4*y[x]==Sec[x]*Tan[x],y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to \cos (2 x) (-\text {arctanh}(\sin (x)))+c_1 \cos (2 x)+2 \sin (x) (-1+c_2 \cos (x)) \]