Identify the horizontal and vertical asymptotes, if any,
of the given function.
f(x) = \frac{x^2 - 4}{4 x - 12}

Separate multiple answers by commas. Enter** DNE ** if an asymptote does not exist.

Separate multiple answers by commas. Enter

a) Horizontal asymptote(s):

b) Vertical asymptote(s):

You can earn partial credit on this problem.