Since the denominator of the fraction is a constant, it's easiest to merely factor out the constant. What I mean is:
At this point you should use the chain rule where to give
Does this answer your question?
I'm having a little trouble with finding the derivative of this one. The fraction with the square root is giving me the trouble, I'm not sure if I should be using the quotient rule or the chain rule or the chain rule within the quotient rule.
Anyone able to clarify this for me?