Question 768084
{{{f(x)=3x/((x-4)(x+4))}}}

Critical points at {{{x=-4}}} and {{{x=4}}}.  Also f crosses x axis at {{{x=0}}}.


The THREE critical points form four intervals of the horizontal x axis.  Vertical asymptotes at x=-4 and x=4.


INTERVALS_______________________SIGN
(-infin, -4)________(-)/(- -)_________(-)
(-4, 0)_____________(-)/(- +)_________(+)
(0, +4)_____________(+)/(- +)_________(-)
(+4, infin)_________(+)/(+ +)_________(+)


{{{graph(300,300,-6,6,-20,20,3x/((x-4)(x+4)))}}}