I ma trying to find a solution for the following ODE:
$$y''+p y'+q y=r y^{2},$$
where prime depicts the derivative with respect to $x$ and $p$, $q$ and $r$ are constant. The left side of the equation is the linear and can be found as a general solution
$$y=c_{1}e^{m_{1}x}+c_{2}e^{m_{2}x},$$
but i don't know how can I specify a function corresponding to the right side to find the particular solution.