# I keep getting mixed up on whether the diagonalized form of A is T^(-1)AT or TAT^(-1). Is there an easy way to remember the correct form?

From MurrayWiki

This is the way I use to remember which form to use. Note the matrix consists of all the eigenvectors, , of : . Using the definition of (right) eigenvectors: , we have:

Right multiply each side by : , which is the correct form.

--Shuo