4.7 problem 95

Internal problem ID [3354]

Book: Ordinary differential equations and their solutions. By George Moseley Murphy. 1960
Section: Various 4
Problem number: 95.
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [_Bernoulli]

\[ \boxed {y^{\prime }-f \left (x \right ) y-g \left (x \right ) y^{k}=0} \]

Solution by Maple

Time used: 0.047 (sec). Leaf size: 81

dsolve(diff(y(x),x) = f(x)*y(x)+g(x)*y(x)^k,y(x), singsol=all)
 

\[ y \left (x \right ) = {\left (\int \left (-k \,{\mathrm e}^{\int \left (f \left (x \right ) k -f \left (x \right )\right )d x} g \left (x \right )+{\mathrm e}^{\int \left (f \left (x \right ) k -f \left (x \right )\right )d x} g \left (x \right )\right )d x +c_{1} \right )}^{-\frac {1}{k -1}} {\mathrm e}^{\frac {\left (\int f \left (x \right )d x \right ) k}{k -1}} {\mathrm e}^{\int -\frac {f \left (x \right )}{k -1}d x} \]

Solution by Mathematica

Time used: 11.421 (sec). Leaf size: 129

DSolve[y'[x]==f[x] y[x]+g[x]y[x]^k,y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} y(x)\to \left (\exp \left (-\left ((k-1) \int _1^xf(K[1])dK[1]\right )\right ) \left (-(k-1) \int _1^x\exp \left ((k-1) \int _1^{K[2]}f(K[1])dK[1]\right ) g(K[2])dK[2]+c_1\right )\right ){}^{\frac {1}{1-k}} y(x)\to \left ((k-1) \left (-\exp \left (-\left ((k-1) \int _1^xf(K[1])dK[1]\right )\right )\right ) \int _1^x\exp \left ((k-1) \int _1^{K[2]}f(K[1])dK[1]\right ) g(K[2])dK[2]\right ){}^{\frac {1}{1-k}} \end{align*}