Let the rational function is .
The numerator of a rational function in lowest terms determines the
-intercepts of its graph.
Observe the graph:
\The -intercepts of the graph are
and
(odd multiplicity; graph crosses the
-axis).
At the graph crosses the
-axis
has odd multiplicity.
At the graph touches the
-axis
even multiplicity.
The horizontal asymptote is .
The numerator is multiplied with .
So one possibility for the numerator is .
\
The denominator of a rational function in lowest terms determines the vertical asymptotes of its graph.
Observe the graph:
\The vertical asymptotes of the graph are and
.
Since approaches
to the left of
and
approaches
to the right of
,
is a factor of odd multiplicity in
.
Since approaches
to the left of
and
approaches
to the right of
,
is a factor of even multiplicity in
. \ \
A possibility for the denominator is .
Therefore, one possibility for the rational function .
\
One possibility; .