You can use the Binomial Theorem to expand ...
.
Since you know that is real, that means the imaginary part is .
So .
You should now be able to solve for .
The question:
Suppose both c and are real (c != 0). Show that c =
How do I solve this? I substituted the value of c into the complex number with the intent to find the magnitude and angle, but I'm not sure how to handle the . Is it two different complex numbers? Am I attempting this correctly? Thanks.