Precalc limit and asymptote help

Use limits to describe the behavior of f(x) = 2/x^2 - 1 at values of x not in its domain

a) lim f(x) = +∞
x ->1-
b) lim f(x) = -∞
x ->1-
c) lim f(x) = +∞
x ->1+
d) lim f(x) = -∞
x ->1-

please help me with limits i am so stuck!!!!

First factor the denominator

f(x) = 2/(x^2 - 1)
= 2/[(x + 1)(x - 1)]

I think you get the idea now :-)

If you limit x → 1- you will have 2/(+)(-) → -∞

If you limit x → 1+ you will have 2/(+)(+) → +∞

(b) and (d) are identical.

So only (a) is incorrect.