Question
Question: If A= \(\begin{bmatrix} i & - i \\ - i & i \end{bmatrix}\), B = \(\begin{bmatrix} 1 & - 1 \\ - 1 &...
If A= $\begin{bmatrix} i & - i \
- i & i \end{bmatrix},B=\begin{bmatrix} 1 & - 1 \
- 1 & 1 \end{bmatrix}$, then A8 equals
A
4B
B
128B
C
–128B
D
– 64B
Answer
128B
Explanation
Solution
we have A = iB
Ž A2 = (iB)2 = i2B2 = –B2
= $\begin{bmatrix} 2 & - 2 \
- 2 & 2 \end{bmatrix}$ = – 2B
Ž A4 = (–2B)2 = 4B2 = 4(2B) = 8B
Ž A8 = (A4)2 = (8B)2 = 64B2 = 128B