In this lecture continue our discussion of higher order linear differential equation. We turn to solve nonhomogeneous equations using the method of undetermined coefficients. This is the same method used in lecture 16 of this series, but now applied to linear ODEs of arbitrary order. The method is demonstrated through numerous examples, many of which highlight the prevalence of repeated roots that need to be handled carefully with higher order equations. This course is taught by Jason Bramburger for Concordia University. More information on the instructor: https://hybrid.concordia.ca/jbrambur/ Follow @jbramburger7 on Twitter for updates.