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Factor the numerator and denominator of . Find the domain of the rational function :
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The rational function is .
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 .
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The domain of is the set of all real numbers of
except
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The domain of function is
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Write in lowest terms :
The function is .
The function is in lowest terms.
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Locate the intercepts of the graph and determine the behavior of the graph of near each
- intercept :
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The rational function is .
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Change to
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Find the intercepts :
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To find -intercept equate the numerator to zero.
The -intercept is
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Find the -intercept by substituting
in the rational function.
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There is no -intercepts.
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Determine the vertical asymptotes :
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Find the vertical asymptote by equating denominator to zero.
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So the function has vertical asymptote at .
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Determine the horizantal asymptotes / oblique asymptotes :
\The function is .
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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.
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Find oblique asymptote :
\Oblique asymptote is found by long division.
\The function is .
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Since the quotient is a squared term, there is no oblique asymptote.
\No oblique asymptote.
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Use the zeros of the numerator and denominator of to divide the
-axis into intervals :
The numerator has one real zero at and the denominator has one real zero at
.
Use these values to divide the -axis into three intervals.
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,
and
.
The solid circle represent the real zeros of the numerator and the denominator.
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Interval | \ \
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Number chosen \ | \
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Value of | \
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Location of graph \ | \
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\ Above \ | \
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
and since the graph of
does not intersect
.
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
and
, the graph of
will approach the vertical asymptote,
at the bottom to the right of
(
).
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Use the results obtained in Steps 1 through 7 to graph the function :
\The graph of :
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1.
\; Domain :
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2.
\The function is in lowest terms.
3.
\The -intercept is
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No -intercept.
4.
\The function is in lowest terms; vertical asymptote :
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5.
\No horizontal or oblique asymptote.
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Interval | \ \
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Number chosen \ | \
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Value of | \
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Location of graph \ | \
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\ Above \ | \
Below ![]() | \
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Above | \
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Point of graph \ | \
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7/8.
\The graph of the rational function :
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