Why is ${(i^{4})}^{2n}$ = 1?

Question

I found this in my math textbook, but there's no proof as to how this conclusion was reached. I'm curious to know how.

Answer 1

$i^4=(i\cdot i)\cdot(i\cdot i) = (-1)\cdot(-1) = 1$, and no matter which power you raise that to, you will still get $1$.