Simplify i^-10

Question

How exactly do I solve for this?

Answer 1

i^-10
= 1/i^10

now look at his pattern
i^2 = -1
i^3 = i(i^2) = -i
i^4 = +1
i^5 = i
.
.
i^10 = -1

so i^-10 = 1/-1 = -1