# Magnitude and phase

Discussion in 'Homework Help' started by welkin87, Dec 5, 2010.

1. ### welkin87 Thread Starter Member

Nov 18, 2010
32
0
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"

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!

2. ### mik3 Senior Member

Feb 4, 2008
4,846
63
$\e^{a+jb}=\e^{a}*\e^{jb}$

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

$A<\Theta=A*\e^{j\Theta}$

Hope this helps.