Let's do the same thing for g prime of a. So f prime of a over g prime of a is going to be this business, which is in orange, f prime of a over g prime of a, which we can write as the limit as x approaches a of g of x minus g of a over x minus a. Well, in the numerator we're taking the limit as x approaches a. In the denominator we're taking the limit as x approaches a. So we can just rewrite this. This we can rewrite as the limit as x approaches a of all this business in orange, f of x minus f of a over x minus a over all the business in green, g of x minus g of a, all of that over x minus a. Now to simplify this, we can multiply the numerator and the denominator by x minus a to get rid of these x minus a.