Question

Whats the "trace" of a Matrix?

Answer 1

Trace of a square matrix is the sum of the elements on the main diagonal.

Explanation:

Trace of a matrix is defined only for a square matrix .

It is the sum of the elements on the main diagonal, from the upper left to the lower right, of the matrix.

For example in the matrix `A`

`A=((color(red)3,6,2,-3,0),(-2,color(red)5,1,0,7),(0,-4,color(red)(-2),8,6),(7,1,-4,color(red)9,0),(8,3,7,5,color(red)4))`

diagonal elements, from the upper left to the lower right are

`3,5,-2,9` and `4`

Hence `traceA=3+5-2+9+4=19`