9.10 problem 20

Internal problem ID [5377]

Book: Schaums Outline. Theory and problems of Differential Equations, 1st edition. Frank Ayres. McGraw Hill 1952
Section: Chapter 14. Linear equations with constant coefficients. Supplemetary problems. Page 92
Problem number: 20.
ODE order: 2.
ODE degree: 1.

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

\[ \boxed {y^{\prime \prime }-y=\frac {1}{\left (1+{\mathrm e}^{-x}\right )^{2}}} \]

Solution by Maple

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

dsolve(diff(y(x),x$2)-y(x)=(1+exp(-x))^(-2),y(x), singsol=all)
 

\[ y = c_{2} {\mathrm e}^{-x}+c_{1} {\mathrm e}^{x}+\frac {{\mathrm e}^{x}}{2}-1+\ln \left ({\mathrm e}^{x}+1\right ) {\mathrm e}^{-x}+\frac {{\mathrm e}^{-x}}{2} \]

Solution by Mathematica

Time used: 0.085 (sec). Leaf size: 42

DSolve[y''[x]-y[x]==(1+Exp[-x])^(-2),y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to \frac {1}{2} e^{-x} \left (-2 e^x+2 \log \left (e^x+1\right )+2 c_1 e^{2 x}+1+2 c_2\right ) \]