Q. If $K = 4 n + 7$ , then $i^{k}$ equals $(n \in I)$

5580 198 Complex Numbers and Quadratic Equations Report Error

A

$- 1$

20%

B

$1$

31%

C

$- i$

32%

D

$i$

17%

Solution:

$i^{k} = i^{4 n} \cdot i^{7} = (i^{4})^{n} (i^{2})^{3} i$
$= 1 (- 1) (i)$
$= - i$