Question

Let f (x) = x + 3. Find and simplify :
f(a+h)−f(a) /h

Answer 1

just plug and chug

f(a+h)-f(a) = (a+h+3)-(a+3) = h

so,

f(a+h)-f(a)
------------ = h/h = 1
   h

Answer 2

I'm sorry its supposed to be the square root of x+3, would it end up being the same ??