Variation of Parameters Formula for Second Order ODEs

This and other videos are organized on my personal website.
mitchaldichter.com/variation_...
Variation of Parameters is a method to find the particular solution of a non-homogeneous linear ODE when the homogeneous solutions are known, which is more powerful than the Method of Undetermined Coefficients since this can solve for any non-homogeneous term if the integrals can be evaluated. The formula requires the homogenous solutions and evaluating some integrals. This page is focused on second order ODEs, but the method applies to higher order ODEs as well.