The rational function is
.
Step 1: Factor the numerator and denominator of
. Find the domain of the rational function.
\
The rational function
.

\
.
Domain : Domain of the function is the set of values of
which makes the function mathematically correct.
.
Denominator of the function should not be zero.
\
Domain of the function is defined for all values of
except at
.
Domain of the function is
.
Step 2: Write
in lowest terms.
\
The rational function in lowest terms is
.
Step 3: Locate the intercepts of the graph.
\Find intercepts :
\The
-intercepts are the zeros of the numerator of
that are in the domain of
.
To find
-intercept, substitute
.
or
\
-intercepts are
,
.
Determine the behavior of the graph of
near each
-intercept.
Near
:
.
Plot the point
and indicate a line with positive slope.
Near
:
. \ \
Plot the point
and indicate a line with negative slope.
Find the
-intercept, substitute
.
\
\
The
-intercept is
.
\
Step 4: Determine the vertical asymptotes.
\The rational function is
.
The Vertical asymptote can be found equating denominator to zero.
\
\
Vertical asymptote
.
\
\
Step 5: Determine the horizontal or oblique asymptote.
\To find horizontal asymptote, first find the degree of the numerator and the degree of denominator.
\\
Degree of numerator
, Degree of the denominator
.
Since the degree of the numerator is greater than degree of denominator, there is no horizontal asymptote.
\Find oblique asymptote.
\Oblique asymptote is found by long division.
\
Quotient is oblique asymptote.
\\
Oblique asymptote is
.
\
\
Step 6: Use the zeros of the numerator and denominator of
to divide the
-axis into intervals
\
The real zero of numerator is
and
and the real zeros of denominator
\
So the real zeros are divide the
- axis into four intervals.
\
\
\
Choosing a number for
in each interval and evaluating
.
| Interval | \ \
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Location of graph | \
| \
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| \
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Below the \
| \
| \
| \
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Above the \
| \
| \
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| \
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\ \ \ \
| \
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Below the \
| \
| \
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Above the \
| \
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Step 7 : Analyze the behavior of the graph of
near each asymptote and indicate this behavior on the graph.
The graph of
is below
-axis for
and above
-axis for
, hence the graph does not intersect the oblique asymptote.
The graph of
is above
-axis in interval
and below
-axis in interval
, hence the graph approaches to vertical asymptote at
.
The graph of
is below
-axis in interval
and is above
-axis in interval
, hence the graph approaches the oblique asymptote.
\
Graph :
\The function
.
\
Domain of the function is
.
-intercepts are
,
.
Plot the point
and indicate a line with positive slope.
Plot the point
and indicate a line with negative slope.
The
-intercept is
.
Vertical asymptote
.
Oblique asymptote is
.
And point on the graph are
,
,
and
.
\
\
Graph of the rational function
: \ \
(1).gif\")