I wasn't sure whether to post this in the math section or not, but here it is. I'm studying for a final exam and reviewing this semesters exam solutions. It's Signals and Systems and I need help with a problem.

"Find the numerical magnitude and phase in radians of this function:
e\(^{(15+j4)f}\) at f=-0.2"

The answer:
magnitude = .04979
phase = -0.8

He only gave the answer for this one, not how he got it. Any help would be much appreciated. Thanks!

 

\(\e^{a+jb}=\e^{a}*\e^{jb}\)

A complex number of the form A<\Theta equals to:

\(A<\Theta=A*\e^{j\Theta}\)

Hope this helps.