Hiya people, I'm a bit stuck on a problem and I have to differentiate this function:

f(x) = 2^(x^2)

i get f '(x) = [2x^3][2^((x^2)-1)] using the chain rule

however one of my mates has got a different answer (and he's a bit more reliable than me!):

f '(x) = [2x][2^(x^2)][ln(2)]

Could anyone please help me on this and possibly explain the derivation as I have to write down the steps in the process

thanks, Watto