The rational function
.
Find the domain of the rational function :
\The domain of a rational function is the set of all real numbers for which the function is mathematically correct.
\Denominator of the function should not be zero.
\
and 
and
.
The domain of function
is
.
Write
in lowest terms :
The function is
.
.
The function
is in lowest terms.
The rational function
.
\
\
Change
to
.
Find the intercepts.
\Find the
-intercept by equating
to zero.


Determine the behaviour of the graph of
near each
-intercept.
Near
:
.
Plot the point
and indicate a line with negative slope.
Find the
intercept, by substituting
in the rational function.


There is no
-intercepts.
\
\
Vertical asymptote can be found by making denominator to zero.
\
or 
or
.
\
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 less than the degree of the denominator,
\hence horizontal asymptote is
.
The real zero of numerator is
and the real zeros of denominator
and
.
So divide the
- axis into four intervals.
\
\
| Interval | \ \
| \
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| \
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| \
Location of the graph | \
| \
| \
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| \
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| \
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| \
\
Below the \ | \
| \
| \
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| \
\
| \
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| \
\
Above the \ | \
| \
| \
\
| \
\
| \
\
| \
\
Below the \ | \
| \
| \
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\
Above the | \
Behavior of the graph :
\As
and
, hence the graph of
approaches to a vertical asymptote at
.
As
and
, hence the graph of
approaches to a vertical asymptote at
.
As
and
, hence the graph of
approaches to a horizontal asymptote at
.
Graph :
\Draw the coordinate plane.
\Plot the horizontal and vertical asymptotes.
\Plot the
and
intercepts and coordinate pairs found in the table.
Connect the plotted points to smooth curve.
\\
\
\
\
The domain of function
is
.
The rational function in lowest terms
.
-intercept is
.
There is no
-intercepts.
Vertical asymptote are
or
.
Horizontal asymptote is
.
| Interval | \ \
| \
\
| \
\
| \
Location of the graph | \
| \
| \
\
| \
\
| \
\
| \
\
Below the \ | \
| \
| \
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| \
\
| \
\
| \
\
Above the \ | \
| \
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| \
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| \
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| \
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Below the \ | \
| \
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| \
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| \
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Above the | \
Graph of the rational function
.
.