Answer:
1
Explanation:
You want to know the value of i^4.
Powers of i
The fourth power of i, √(-1), can be found the same way the value of any fourth power can be found: carry out the multiplication.
i^4 = i·i·i·i = -1·i·i = -i·i = -(-1) = 1
The fourth power of i is 1.
__
Additional comment
As you can see from the evaluation process, ...
i¹ = i
i² = -1 . . . . . definition of i
i³ = -i
i⁴ = 1
The sequence repeats for higher powers.