Question

question
evaluate:
$i^{74}$
answer
○ $-1$ ○ $-i$
○ $i$ ○ $1$

Explanation:

Step1: Find exponent remainder mod 4

$74 \div 4 = 18$ remainder $2$, so $i^{74}=i^{4\times18 + 2}=(i^4)^{18} \times i^2$

Step2: Use $i^4=1$ and $i^2=-1$

$(1)^{18} \times (-1) = 1 \times (-1)$

Answer:

-1