The trace of the matrix A = [(1,-5,7)(0,7,9)(11,8,9)] is : A. 17 B. 25 C. 3 D. 12 ​

Question

The trace of the matrix A = \(\begin{bmatrix} 1 & -5 & 7 \\[0.3em] 0& 7 &9 \\[0.3em] 11 & 8 &9 \end{bmatrix}\) is : 

A. 17 

B. 25 

C. 3 

D. 12

Answer 1

(A). 17

As the trace of a matrix is the sum of on – diagonal elements,

So, 

1 + 7 + 9 = 17 

Trace = 17 

Option (A) is the answer.