using the definition of the derivative find:

f(x) = 2 / sqrt(x)

any help is appreciated!

I got stuck right after:

f'(x) = lim (h--> 0) (2/ sqrt(x+h) - 2/ sqrt(x)) / h

I just need to know where to go after this.

Do I find the lcm of sqrt(x+h) and sqrt (x)? What is the lcm and what do I need to multiply both denominators by?