Given that f is a differentiable function and g(x) = xf(x). Use the limit definition of derivative show that g'(x) = xf'(x) + f(x).
I understand that you have to find the derivative of xf(x) using the difference quotient but when I set up the problem I can't really simplify it.
This is what I have so far:
Lim as h -> 0
(x+h) f(x+h) - xf(x) / h