Question

Let f(x)=-2x/(x^2-x-8). There are two numbers that are not in the domain of f. Give the larger value to 2 decimal places.

Answer 1

@FibonacciChick666 I was wondering if you could help me with this?

Answer 2

what number on the bottom makes a fraction go crazy?

Answer 3

(not work, be infinite, undefined, indeterminate)

Answer 4

what number can't you divide by?

Answer 5

I am a little confused what do you mean?

Answer 6

well, there is one number you cannot divide by. What is it?

Answer 7

If you google it, it will probably be the first result

Answer 8

you can divide by 0

Answer 9

right, you can't divide by zero

Answer 10

so, if you make the bottom of the fraction =0 all Helsinki will break loose. ie. the x value will not be a part of the domain

Answer 11

so, just solve x^2-x-8=0 and you will have your two points :)

Answer 12

1/2 + square root 33 / 2 = 3.37

Answer 13

wolfram likes it http://www.wolframalpha.com/input/?i=x%5E2-x-8%3D0

Answer 14

or 1/ 2 + square root 33 / 2 = -2.37 but they are looking for the larger number which is 3.37

Answer 15

sounds right to me

Answer 16

I have one more problem I am working on in a graph is f(x) the same as y? Like if they said x approaches infinity what does f(x) approach is that basically y?

Answer 17

Thanks for your help again :)

Answer 18

yea, f(x) and y are the same thing

Answer 19

np

Answer 20

Ok because this is the graph I am looking at

Answer 21

The thing that has been throwing me off is that there is 3 lines

Answer 22

yea, but you only care about where x goes to infinity

Answer 23

would that be the one at the top right and y is also going to infinity

Answer 24

well the right side, and it looks like it's going up to me

Answer 25

to positive infinity?

Answer 26

Oh I see it thanks again :)

Answer 27

np