How to find eigenvectors of a matrix, once you know the eigenvalues. The previous video explained how to find eigenvalues, https://www.youtube.com/watch?v=5HNV6s_d-cs&list=UUcueusnCB7aNN4Af6v6tSCQ
This video is in a series by Simon Benjamin, an Oxford Professor, which introduces Vectors, Matrices, Determinants and Eigenvectors. The series is meant for people starting University in science or engineering.