F(x+h)-f(x), if f(x)=4x+3?

Question

how would i go about doing this? and also [F(x+h)-f(x)]/H, if f(x)=4x+3?

A picture of the page that im working: http://i83.photobucket.com/albums/j319/mancool12/CCF11252007_00001.jpg

hope this helps

Answer 1

what is f(1)?
Answer: 4(1) + 3
What is f( 2)?
Answer: 4(2) + 3

What is f(x^2)?
Answer: 4(x^2) +3

So can you find f(x+h)?

You know f(x), subtract.

Answer 2

f(x) = 4x + 3
f(x + h) = 4(x + h) + 3

f(x + h) - f(x) = 4(x + h) - 4x

[ f(x + h) - f(x) ] / h
= [4(x + h) - 4x] / h
= [ 4h / h]
= 4

Note
If f(x) = 4x + 3
f `(x) = 4