Question

Finding Limits. See attachment.

Answer 1

fyi, i will use "h" for "delta x"

you are given f(x) = 4x^2 -8x
to get f(x+h) , replace "x" with "x+h"

--> f(x+h) = 4(x+h)^2 - 8(x+h)

Now plug that into limit formula and simplify.... the goal is to factor out an "h" to cancel with "h" in denominator

Answer 2

Let me work that out really quick?

Answer 3

I got (8hx +4h^2 - 8h)/hx so far

Answer 4

looks good ... except there should only be an "h" in denominator

Answer 5

Hmm. Guessing the x in the numerator cancels the one in the denominator. Only think I can think of.

Answer 6

no, can't do that because of the addition operation in numerator

there should never be an x in denominator to start with ... look at limit formula, the denominator is "delta x" or "h"

Answer 7

Oh, okay. Guess I got some things confused...

Answer 8

Not entirely sure where to go from there. The delta keeps throwing me off.

Answer 9

oh yeah well you are really close ... you simplified numerator correctly, now just factor out an h

--> h(8x+4h-8) / h

the h will cancel leaving

8x +4h -8

now take limit as h->0