The question states find the distance between the following points (a,sqrt(a)) (a+h,sqrt(a+h))

To begin with i know i should plug it into the distance formula so..

sqrt((a+h-a)^2 + (sqrt(a+h)-sqrt(a))^2)

from here I subtract a from a+h leaving sqrt((h)^2 + (sqrt(a+h)-sqrt(a))^2)

I'm unsure of how to proceed from here. If I remeber correctly (sqrt(a+h)-sqrt(a) is already simplified so i would assume I multiply (sqrt(a+h)-sqrt(a) (sqrt(a+h)-sqrt(a) use foil and then add the (h)^2 to the product but that answer doesn't check.

I then tried to rationalize the numerator but that seems like i'm over complicating it. i've been trying to solve this off and on for a week now with no luck its just an optional homework assignment that isn't graded, but I would really like to know how to figure this out. Any help would greatly be appreciated.