# Thread: Trigonometry

1. ## Trigonometry

True or False: When cubing a complex number using DeMoivre's Theorem, there are three answers. Why is this + is it always the case?

2. Originally Posted by Marcie
True or False: When cubing a complex number using DeMoivre's Theorem, there are three answers. Why is this + is it always the case?
When you cube any number, do you get three answers? No.

When you cube root a complex number using DeMoivre's theorem, you get three answers (in fact, these answers form what is called the third roots of unity); This is inpart due to the fact that $x^3-1=0$ has three complex roots due to the Fundamental Theorem of Algebra.