1. Thanks

2. Unfortunately, we have not yet studied expensions of complex functions (this is also giving me a hard time proving the chain rule, bah).

However, a friend of mine has only 10 minutes ago told me of something he thought of:

lim sinz/z = lim (sinz-sin(0))/(z-0) = sin'(0) = cos(0)

of course I only need to show sin'x = cosx, but I think that's not gonna be hard...

Anyway, I really appreciate the suggestions, and if you have other original ideas I'd be glad to hear.

Gotta go right now

Thanks again!

Tomer.