DIfferential calculus

Question

Find from first principles f'(x) given f(x) is 2√x

Answer 1

In other words, you are being told to develop the derivative by using the limit of a difference quotient for this function.

 

This is a classic problem usually appearing in Calculus books.  I prefer not to re-invent the wheel, so to speak, because it's hard typing...but the real reason is that you will find very similar examples in any reputable calculus text.