Question

Define trace of a matrix.

Answer 1

In a square matrix, the sum of elements of the principal diagonal is called the ‘trace of a matrix’. We denote the trace of the matrix A by ‘tr A’.

Example : If A =$\left[\begin{array}{ccc}1& 1& 4\\ 2& 6& 7\\ 0& 4& 5\end{array}\right]$ , then tr A = 1 + 6 + 5 = 12.