Question

How would I find the domain and range of (2)/(x^2-2x-3)? Is the domain x=-1 x=3

Answer 1

try factoring the denominator
what values of x are not possible?

Answer 2

x=-1 and x=3

Answer 3

the domain is all possible values of x

Answer 4

right

Answer 5

so -1 and 3 are not in the domain

Answer 6

The domain is the values that x can have.
y = 2/(x^2 - 2x - 3)
has a denominator. Since division by zero is not allowed, you need to find which values of x would make the denominator zero. To do that, solve (which you did)
x^2 - 2x - 3 = 0
(x - 3)(x + 1) = 0
x = 3 or x = -1
These are the value of x that must be excluded from the domain, so the domain is all real numbers except x = 3 and x = -1.

Answer 7

oh so all reals except x=-1 and x=3 for the domain

Answer 8

yup

Answer 9

ok thanks! but what about the range?

Answer 10

the range is all possible values of f(x)

Answer 11

so can you figure that out?

Answer 12

um how would i set it up?

Answer 13

dang ok.. don't solve it for me but how would i go about that?

Answer 14

well for a start the values of f(x) corresponding to x=3 or -1 will be excluded

Answer 15

Couldn't I find the inverse of the function and then find the domain?

Answer 16

@cwrw238

Answer 17

yes the inverse of the function has domain which equals range of the function

Answer 18

ok thanks for your time and patience!

Answer 19

yw