Function question!!

(question in comments)

Question

Function question!!

(question in comments)

anonymous · Answer

Given f(x) =x^2- 1, find the value $$\frac{ f(x+h) - f(x) }{ h }$$

anonymous · Answer

I just need help in getting started please! :)

anonymous · Answer

Would the next step be$$\frac{ ((x^2 - 1) +h) - (x^2 - 1) }{ h }$$

anonymous · Answer

your step isn't correct.

(x^2+2xh+h^2-1-x^2+1)/h=2x+h
that's the answer :)

anonymous · Answer

How did you get there? But thank you!

phi · Answer

f(x+h) means replace  x  with (x+h)  in the expression   x^2 -1

in other words    ( (x+h)^2 -1)

anonymous · Answer

Oh so I just substituted into the wrong equation. I see now! Thank you. that was super helpful

phi · Answer

it's confusing because they use x  in both places.

if we had
f(y) =  y^2 - 1
and we want f(x+h)
we replace y with (x+h):    ( (x+h)^2 )  - 1

anonymous · Answer

Ohh I see. Okay, thank you for explaining!! :)