The rational function is .
.
Factor the numerator and denominator of . Find the domain of the rational function :
The domain of a rational function is the set of all real numbers except those for which the denominator is .
To find which number make the fraction undefined create an equation where the denominator is not equal to .
The domain of is the set of all real numbers of
except
.
The domain of function is
.
\
Write in lowest terms :
The function is .
The function is in lowest terms.
\
Locate the intercepts of the graph and determine the behavior of the graph of near each
- intercept :
The rational function is .
Change to
.
Find the intercepts :
\Find the -intercept by equating the numerator to zero.
There is no real solutions.
\There is no -intercepts.
Find the -intercept by substituting
in
.
There is no -intercept.
\
Determine the vertical asymptotes :
\Find the vertical asymptote by equating denominator to zero.
\
Vertical asymptote is at .
The function not defined at .
.
Since the function is in lowest terms, there is no hole.
\
Determine the horizontal asymptotes / oblique asymptotes:
\The function is .
To find horizontal asymptote, first find the degree of the numerator and degree of the denominator.
\Degree of the numerator and 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.
\The function is .
Quotient is oblique asymptote.
\Oblique asymptote is .
The graph does not intersect the line .
Use the zeros of the numerator and denominator of to divide the
-axis into intervals :
The numerator has no real zeros and the denominator has one real zero at .
Use these values to divide the -axis into two intervals.
and
.
Interval | \ \
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Number chosen \ | \
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| \
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Value of | \
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| \
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Location of graph \ | \
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\ Below \ | \
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Above | \
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Point of graph \ | \
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End behavior of the graph :
\Since the graph of is below the
-axis for
and is above for
and since the graph of
does not intersect the oblique asymptote,
, the graph of
will approach the line
.
Since the graph of is below the
-axis for
, the graph of
will approach the vertical asymptote,
at the top to the left of
(
).
Since the graph of is above the
-axis for
, the graph of
will approach the vertical asymptote,
at the top to the right of
(
).
Use the results obtained in Steps 1 through 7 to graph the function :
\The graph of :
.
1:
\; Domain :
.
2: The function is in lowest terms.
3: No intercepts.
\4: The function is in lowest terms.
Vertical asymptote : .
5:
\Oblique asymptote : , not intersected.
6:
\Interval | \ \
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Number chosen \ | \
\
| \
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| \
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Value of | \
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| \
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\ | \
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Location of graph \ | \
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\ Below \ | \
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Above | \
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Point of graph \ | \
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| \
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| \
7 and 8:
\The graph of the rational function :
.