Question

Finding the x int of:

(x^2-1)/(x^2-2x-3)

Answer 1

I know that you set it equal to zero and solve. But I'm having trouble solving it.

Answer 2

when does a fraction equal zero?

Answer 3

So your saying there is no x-int?

Answer 4

no, im saying ... when does a fraction equal zero?

Answer 5

when zero is in the numerator?

Answer 6

correct, what possible values does that give us for this? keeping in mind the the bottom cant zero out either

Answer 7

when does x^2 - 1 = 0 ?

Answer 8

would it be only positive 1?

Answer 9

well, (+1)^2 = 1, and (-1)^2 = 1

check if 1 and -1 dont make the bottom go zero, if not then they are good

Answer 10

if x^2-2x-3 = 0 when x=1 ; then we cant include 1 as a solution

if x^2-2x-3 = 0 when x=-1 ; then we cant include -1 as a solution

otherwise, we keep them as solutions

Answer 11

do you see why? when the bottom of a fraction is zero, its undefined

Answer 12

i just checked and both -1 and 1 do not make the denominator =0

Answer 13

so they both will be the x int?

Answer 14

x^2-2x-3
-1 -1
------------
1 + 2- 3 = 0 ; -1 does make a zero underneath

Answer 15

the x=1 makes a -4 i believe so its the only good answer

Answer 16

your right...i messed up

Answer 17

the graph should verify it :)

http://www.wolframalpha.com/input/?i=%28x%5E2-1%29%2F%28x%5E2-2x-3%29

Answer 18

thanks for the help!

Answer 19

good luck :)