Question

{[3(x+h)^2 +(x+h)]- (3x^2+x)} / h

Answer 1

\[\frac{ [3(x+h)^{2}+(x+h)]-(3x ^{2}+x) }{ h }\]

Answer 2

hint: use foil to expand (x+h)^2

Answer 3

Ive expanded it and tried to solve it but my answer is not a choice on my homework

Answer 4

what did you get as the answer? you may have made a simple math error somewhere

Answer 5

i think the problem is my division after i distribute and cancel out like terms i get
(6xh+3h^2+h)/h
i get
6x +8h at the end

Answer 6

not quite, h should not be in the final answer at all.

let's start from the beginning, ok?

Answer 7

okay so then it would be
[3(x^2 + 2xh +h^2 ) + x+h -3x^2 -x]/h

Answer 8

alright so far so good

Answer 9

then we use distribution to expand the numerator

Answer 10

then we cancel out terms

Answer 11

i have a question does 3 not distribute to h^2 = 3h^2 ?

Answer 12

whoops

Answer 13

(and I made a small mistake earlier, h should be in the answer. I was thinking of derivatives for some reason)

Answer 14

now, we factor out h from the numerator

Answer 15

yeah this is actually trying to solve for a derivative using
[f (x+h)- f(x)] / [(x+h)-x]

Answer 16

right, so if we're going for a derivative, all we need to do now is set h = 0

Answer 17

ohh so i have to factor out the 'h' okay and then the 0

Answer 18

so the derivative of 3x^2 + x = 6x + 1