# Math Help - Diagonalization question

1. ## Diagonalization question

Am I being stupid? This seems like an easy question, especially given all the linear algebra I've been doing so far. For some reason, this has me stumped.

Given a real matrix A, I have to prove that ${A^t}A$ is diagonalizable ( ${A^t}$ being the transpose of A). The other questions that I've already done are about inner product spaces, although this question may be independent of that.

2. Originally Posted by tiana3
Am I being stupid? This seems like an easy question, especially given all the linear algebra I've been doing so far. For some reason, this has me stumped.

Given a real matrix A, I have to prove that ${A^t}A$ is diagonalizable ( ${A^t}$ being the transpose of A). The other questions that I've already done are about inner product spaces, although this question may be independent of that.

1) If a matrix is normal then it is diagonalizable

2) If A is a real matrix, then A*=A^t

Tonio