3.78 problem 1080

Internal problem ID [9412]

Book: Differential Gleichungen, E. Kamke, 3rd ed. Chelsea Pub. NY, 1948
Section: Chapter 2, linear second order
Problem number: 1080.
ODE order: 2.
ODE degree: 1.

CAS Maple gives this as type [[_2nd_order, _with_linear_symmetries]]

\[ \boxed {y^{\prime \prime }-\left (\frac {f^{\prime }\left (x \right )}{f \left (x \right )}+2 a \right ) y^{\prime }+\left (\frac {f^{\prime }\left (x \right ) a}{f \left (x \right )}+a^{2}-b^{2} f \left (x \right )^{2}\right ) y=0} \]

Solution by Maple

Time used: 0.093 (sec). Leaf size: 65

dsolve(diff(diff(y(x),x),x)-(diff(f(x),x)/f(x)+2*a)*diff(y(x),x)+(a*diff(f(x),x)/f(x)+a^2-b^2*f(x)^2)*y(x)=0,y(x), singsol=all)
 

\[ y \left (x \right ) = {\mathrm e}^{\int \frac {{\mathrm e}^{2 b \left (\int f \left (x \right )d x \right )} \left (\left (-f \left (x \right ) b +a \right ) {\mathrm e}^{-2 b \left (\int f \left (x \right )d x -c_{1} \right )}-f \left (x \right ) b -a \right )}{-{\mathrm e}^{2 b \left (\int f \left (x \right )d x \right )}+{\mathrm e}^{2 c_{1} b}}d x} c_{2} \]

Solution by Mathematica

Time used: 0.112 (sec). Leaf size: 47

DSolve[y[x]*(a^2 - b^2*f[x]^2 + (a*Derivative[1][f][x])/f[x]) - (2*a + Derivative[1][f][x]/f[x])*y'[x] + y''[x] == 0,y[x],x,IncludeSingularSolutions -> True]
                                                                                    
                                                                                    
 

\[ y(x)\to e^{a x} \left (c_1 \exp \left (b \int _1^xf(K[1])dK[1]\right )+c_2 \exp \left (-b \int _1^xf(K[2])dK[2]\right )\right ) \]