How do you solve radical equations?

I^5 -6i^4-3i^-3i

i^5 -6i^4-3i^-3i

There is a pattern to the i powers

i=1\\i^{2}=-1\\i^{3}=-1\\i^{4}=1, then it starts over.

Suppose you wanted i^{1703}.

Just divide 1703 by 4 and look at the remainder. 425 with remainder of 3. Therefore, it is equal to -1. See?

3i^{-3i}=3e^{\frac{3\pi}{2}}