need help with something called a gamma function?

Question

I'm taking multivariable calculus and the prof didn't teach us how to use this function and it is not described in my textbook but it appears in one of the homework problems where it gives a short description before the actual problem where it gives a symbol like "[" (without the bottom line on the bracket) "is a gamma function" what is this and how do I evaluate this function?
I will post this question on the math forum as well.

Answer 1

you can find this in

http://mathworld.wolfram.com/GammaFunction.html

Answer 2

That's a test you should perform when buying a new calculator. Try putting in a non-integer value and press the n! button to see if it is able to evaluate it. HP's do, but not too many others. I hope the teacher already told you that
n! = gamma(n + 1) = n gamma(n)
although some may tell you that n! is defined only for integers. I see that more as a personal choice than a law. The gamma function seems to play a part in physics, fundamentally. It has been involved since the very beginnings of string theory.

Answer 3

Here you go:
http://en.wikipedia.org/wiki/Gamma_function

It basically extends the factorial function, "!", so it can take non-integer inputs.