Question
Question: If A and B are square matrices such that AB = B and BA = A, then A<sup>2</sup> + B<sup>2</sup> is eq...
If A and B are square matrices such that AB = B and BA = A, then A2 + B2 is equal to-
A
2AB
B
A+ B
C
AB
D
2BA
Answer
A+ B
Explanation
Solution
A2 + B2 = AA + BB = A(BA) + B(AB)
= (AB) A + (BA)B = BA + AB = A + B