Question

If `D_(1)` and `D_(2)` are two `3xx3` diagonal matrices, then which of the following is/are true ?
A. `D_(1)D_(2)` is a diagonal matrix
B. `D_(1)D_(2)=D_(2)D_(1)`
C. `D_(1)^(2)+D_(2)^(2)` is a diagonal matrix
D. none of these

Answer 1

All are properties of diagonal matrix.