Question

Find the difference quotient for f(x)=5-7x+8x^2

Answer 1

Know the difference quotient formula?

Answer 2

yes

Answer 3

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

Answer 4

Oh lets use this one f(x+h)-f(x)/h, since we don't have a.

Answer 5

ok

Answer 6

I already found f(a) and f(a+h)

Answer 7

Okay can I see them please.

Answer 8

f(a)=5-7a+8a^2
f(a+h)=5-7(a+h)+8(a+h)^2

Answer 9

No, doesn't look correct. "a" is used to denote a special number that you must find the derivative at. We don't have that special number so we can't just change x to a. That's why I said we should the formula I gave.

Answer 10

It is correct because I checked the answer and it is right

Answer 11

I will figure it out, thanks for the help

Answer 12

Okay...if you can use x or a then we would get the same answer.

Answer 13

So did you get 16a+8h-7? @hannahmarie620

Answer 14

for what?

Answer 15

For the difference quotient.

Answer 16

no

Answer 17

What did you get?

Answer 18

wait sorry yes I did get that

Answer 19

I forgot to cancel the h's out

Answer 20

Good! I have a confession I got 16x+8h-7. I still used x instead of a. :P