Answer Key for Exercise Set 12: Graphing and Analyzing Rational Functions, Study notes of Algebra

The solutions to Exercise Set 12 of a calculus course, focusing on finding the domain, vertical and horizontal asymptotes, intercepts, and graphing rational functions. It includes five exercises with detailed step-by-step solutions.

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Review Exercise Set 12
Exercise 1: Find the domain of the given rational function.
( )
2
5
43
x
hx xx
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Exercise 2: Use the given graph to complete the statements below.
a)
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,As x f xโ†’ โˆ’โˆž โ†’
b)
( )
2,As x f x
โˆ’
โ†’โˆ’ โ†’
c)
( )
2,As x f x
+
โ†’โˆ’ โ†’
d)
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2,As x f x
โˆ’
โ†’โ†’
e)
( )
2,As x f x
+
โ†’โ†’
f)
( )
,As x f xโ†’โˆž โ†’
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pf4
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pf9

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Download Answer Key for Exercise Set 12: Graphing and Analyzing Rational Functions and more Study notes Algebra in PDF only on Docsity!

Review Exercise Set 12

Exercise 1: Find the domain of the given rational function.

( ) 2 5 4 3

h x x x x

Exercise 2: Use the given graph to complete the statements below.

a) As x โ†’ โˆ’โˆž, f (^) ( x )โ†’ b) As x โ†’ โˆ’2 , โˆ’ f (^) ( x )โ†’ c) As x^ โ†’ โˆ’2 ,^ + f^ ( x )โ†’ d) As x โ†’ 2 ,โˆ’ f (^) ( x )โ†’ e) As x โ†’ 2 ,+ f (^) ( x )โ†’ f) As x โ†’ โˆž, f (^) ( x )โ†’

Exercise 3: Find the vertical and horizontal asymptotes of the given rational function.

( ) (^2)

g x x x x

Exercise 4: Graph the given rational function by finding any symmetry, intercepts, asymptotes, and any additional points.

( )

2 2

r x x x x

Review Exercise Set 12 Answer Key

Exercise 1: Find the domain of the given rational function.

( ) (^2)

h x x x x

Set the denominator equal to zero and solve for x x 2 + 4x + 3 = 0 (x + 1)(x + 3) = 0 x + 1 = 0 or x + 3 = 0 x = -1 or x = -

Exclude the values that make the denominator zero from the domain

Domain: (^) ( โˆ’โˆž โˆ’, (^3) ) โˆช โˆ’( 3, โˆ’ (^1) ) โˆช โˆ’( 1, โˆž)

Exercise 2: Use the given graph to complete the statements below.

a) As x โ†’ โˆ’โˆž, f (^) ( x )โ†’ b) As x โ†’ โˆ’2 , โˆ’ f (^) ( x )โ†’ c) As x โ†’ โˆ’2 , + f (^) ( x )โ†’ d) As x โ†’ 2 ,โˆ’ f (^) ( x )โ†’ e) As x โ†’ 2 ,+ f (^) ( x )โ†’ f) As x โ†’ โˆž, f (^) ( x )โ†’

Exercise 3: Find the vertical and horizontal asymptotes of the given rational function.

g (^) ( x (^) ) = (^) x (^23) โˆ’^^ x + x^7 โˆ’ 6

Vertical asymptote Set the denominator equal to zero and solve for x x 2 - x - 6 = 0 (x + 2)(x - 3) = 0 x + 2 = 0 or x - 3 = 0 x = -2 or x = 3 The vertical asymptotes will be at x = -2 and x = 3 Horizontal asymptote Compare degrees of the numerator and denominator degree of numerator: 1 degree of denominator: 2 Since the denominator has a larger degree, the horizontal asymptote will be the x-axis or y = 0.

Exercise 4: Graph the given rational function by finding any symmetry, intercepts, asymptotes, and any additional points.

( )

2 2

r x x x x

Vertical asymptote

x 2 + 4x - 12 = 0 (x + 6)(x - 2) = 0 x + 6 = 0 or x - 2 = 0 x = -6 or x = 2

Horizontal asymptote

degree of numerator: 2 degree of denominator: 2

degrees are the same so the horizontal asymptote will be the ratio of the leading coefficients.

y = 2 1

= 2

Exercise 4 (Continued):

Graph

Exercise 5: Graph the given rational function by finding any symmetry, intercepts, asymptotes, and any additional points.

( )

3 2 r x x^2 x x

Vertical asymptote

x 2 + x = 0 x(x + 1) = 0 x = 0 or x + 1 = 0 x = 0 or x = -

Horizontal asymptote

degree of numerator: 3 degree of denominator: 2

The numerator has the larger degree so there is no horizontal asymptote. However, since the difference in the degrees is 1 there will be a slant asymptote.

Exercise 5 (Continued):

Slant asymptote

Divide the rational function using long division

The quotient of x - 1 is the slant asymptote.

Intercepts

Let x = 0

x cannot be zero since this is the location of one of the vertical asymptotes

Let r(x) = 0 3 2 3 3 3

x x x x x x x

x-intercept ( โˆ’^3 2, 0)

Symmetry

(^3 ) 2 2 3 3 2 2

r x r x x (^) x x x x^ x x x x x x x

r(-x) and r(x) are not the same functions so it is not symmetric about the y-axis.