\begin{definition}[Definition:Nonhomogeneous Linear Second Order ODE]
A '''nonhomogeneous linear second order ODE''' is a differential equation which is in (or can be manipulated into) the form:
:$\dfrac {\d^2 y} {\d x^2} + \map P x \dfrac {\d y} {\d x} + \map Q x y = \map R x$
where:
:$\map P x$, $\map Q x$ and $\map R x$ are functions of $x$ alone (or constants)
:$\map R x$ is not the zero constant function.
That is, a '''nonhomogeneous linear second order ODE''' is a linear second order ODE which is not homogeneous.
\end{definition}