Please someone help me.. I've an exam in 2 days ... The following problem makes me nuts.. I can't get it right..
Show that:
cos(∏ - alpha) + i cos (∏/2 - alpha)
-------------------------------------------- = cis (∏ - 2alpha)
cis (alpha)
I'm desperate... I've tried everything I know.. any help is appreciated
Okay, you've got the and expressions. So you need to evaluate:
You could do the division but recall Euler's theorem: . See what you can do with this.
-Dan