### Video Summary:

De Moivre’s Theorem
If r(cos + i sin ) is a complex number, and n is any real number. nth Root
For a positive integer n, the complex number a+bi is the nth of the complex number x + yi if (a + bi)n = x + yi.
nth Root Theorem
If n is any positive integer, r is a positive real number, and is in degrees, then the nonzero complex number r(cos + i sin ) has exactly n distinct nth roots