Matrices from a geometric perspective
3Blue1Brown has an <i>outstanding</i> series of short videos, "Essence of linear algebra"[1], which covers vectors, matrix transformations, and the related math. What I particularly like about these videos is that the concepts are introduced first without the numbers and calculations (that stuff is covered later). The concepts are first introduced as abstract animations to emphasize the "shape" of what the vector, matrix, <i>etc</i> really represent.<p>[1] <a href="https://www.youtube.com/playlist?list=PLZHQObOWTQDPD3MizzM2xVFitgF8hE_ab" rel="nofollow">https://www.youtube.com/playlist?list=PLZHQObOWTQDPD3MizzM2x...</a>