Question

if A is hermitian such that A^2=0 show that A=0

Answer 1

This is a proof question and I am not sure how to prove it. It is obviously true if you start with A=0and square it.

A²=0

then AA=0

multiply both sides by A-¹

AAA-¹= 0A-¹

I A = 0

but the zero matrix is not invertible and that it was not among the given conditions.