Question

Find the domain
f(x)= 2x/x^2-4x-5

Answer 1

Is the entire (x^2 - 4x - 5) in the denominator?

Answer 2

yes

Answer 3

factor the denominator:
x^2 - 4x - 5 = x^2 - 5x + x - 5
x(x-5) + 1(x-5)
(x+1)(x-5)

f(x) = 2x / { (x+1)(x-5) }

The denominator cannot be zero.

Therefore the domain should exclude what 2 values of x?

Answer 4

-1 and 5