Question

Will somebody please explain to be how to do this problem?
Let f(x)=5·x2−2·x.
Find (f(x+h)−f(x))/h if h≠0.
Simplify your answer.

Answer 1

do you know how to solve f(h) from your original equation, for example?

Answer 2

you plug in "h" for every "x" in the equation of the function, right?

Answer 3

I thought you would plug in f(x) = 5x^2-2X for each x in the second equation.

Answer 4

you would plug in (x+h) in every x for the first part of the equation so it would be something like ((5*2(x+h)-2*(x+h))-(5*2x-2x)) then distribute. does that make sense?

Answer 5

I tried to plug all that in and my answer came out to be 8x-h and it wasn't right.

Answer 6

\[(f(x+h) - f(x) ) / h\]

Answer 7

i got 10x-10x=0... 0_0 im a bit rusty lol is that and option?

Answer 8

\[5(x+h)^2 - 2(x+h) - (5x^2 - 2x) / h\]

Answer 9

I tried zero. That was working either.

Answer 10

oh zazoo is right just listen to them.

Answer 11

sorry i couldnt help

Answer 12

then you would expand and simplify

Answer 13

Okay. Zazzo: for that I got 5h-4x-2. What am I doing wrong?

Answer 14

Zazoo*

Answer 15

\[5(x+h)^2 - 2(x+h) - (5x^2 -2x)\]

Answer 16

\[(5x^2 + 10xh + 5h^2) - 5x^2 - 2x\]