## Shortcuts to diagonalize a 2×2 matrix

Matrix diagonalization is one of my favourite topics in linear algebra. I still remember learning it for the first time and being quite awed by it. What is diagonalization? If $A$ is a square matrix, the diagonalization is finding an invertible matrix $P$ such that $P^{-1}AP = D$ where $D$ is a diagonal matrix. It’s […]