# How to prove trace(A.A*) is positive

by devoured_elysium
Tags: positive, prove, traceaa
 Sci Advisor HW Helper P: 9,396 How to prove trace(A.A*) is positive That would not be a very easy way of doing this question. The trace of (AA*) is $$\sum_{i,j} A_{ij}(A^*)_{ji}$$ What is the definition of A*?