Get 10 Precalculus Practice Tests (200 questions solved) https://www.patreon.com/collection/1722797 Shop math t-shirts & hoodies: https://amzn.to/3qBeuw6 --- This math tutorial explores the cases when (x+y)^4 is actually equal to x^4+y^4, besides x=0 or y=0. We will encounter complex numbers! Enjoy!...