Question

Find the slope of the secant line passing
through the points
(1, f(1)), (1 + h, f(1 + h))
when
f(x) = 2x2 − 2x − 4.

Answer 1

well the slope would be \[[f(1)-f(1+h)]/h\] or \[[-4-(2[1+h]^{2}-2[1+h]-4)]/h\] which is equal to \[-3-2h\]

Answer 2

actually I made a mistake first term in the equation is suppose to written as2x^2-2x-4

Answer 3

i realized that :) its still the right answer

Answer 4

but the answer choice do not have -3-2h, its either
a) slope = 2h + 2
b) slope = 4h − 6
c) slope = 2h − 2
d) slope = 2h + 6
e) slope = 4h − 2
f) slope = 4h + 6

Answer 5

oh yes.. the answer is a).... apologies I didn't simplify right :P.. \[[-4-(2[1+h]^{2}-2[1+h]-4]/h\] actually is \[-2-2h\] which is still wrong but off by a factor of -1 because I the denominator of the fraction is -h not h... so many mistakes.. sorry about that

Answer 6

that ok, thanks for help

Answer 7

Wait, can you step by step show how you calculate -2-2h because I'm still now getting it myself?

Answer 8

???

Answer 9

So when finding the slope of something you use the slope formula
(y2-y1)/(x2-x1) those are not squared they are subscripts
f(1+h)-f(1)/(1+h)-1 the ones will cancel out
now those f values in every where you see an x in your polynomial equation

Answer 10

I had it all written out then I was logged off, sorry i will try to write it out again

Answer 11

its ok, the same happen to me before, lol

Answer 12

2+4h+2h^2-2-2h-4-2+2+4/h, now cross out
2h+2h^2/h now factor out 2h
2h(1+h)/h cross out the h's
2(1+h) or 2+2h or 2h+2

Answer 13

which is a. :)

Answer 14

did you use the slope formula?

Answer 15

yes I did, i showed that in my first comment

Answer 16

It might help if you write out what i did so you can see it on paper

Answer 17

it just hard to tell because of the way its on the work is on the computer if you were using the slope formula?

Answer 18

yea its hard to type math formulas but i did use it.