Check the picture below.
so, hmmm notice, since i² = -1 and i⁴ = 1, whenever the exponent is only divisible by 2, the value will be -1, and whenever the exponent is divisible by 4, we end up with a +1, so every subsequent even exponent is simply cancelling the previous value, if we take that to the even value of 100, which has 50 pairs of those, we end up with, yeap, you guessed it, 0.
