The original problem as written was stated in terms of . In this last post you wrote . Which was it supposed to be?
Otherwise recall the general rule
Let's first talk about the
by the rule I just mentioned. e^0 = 1, not e.
Similarly
Finally
I'd recommend you review your exponent rules.
-Dan
Edit: If your problem really is
then the answer is
See if you can get that with what we showed you in this thread.