Textbook Question
Graph each polynomial function. Factor first if the polynomial is not in factored form. ƒ(x)=2x4+x3-6x2-7x-2
Ch. 3 - Polynomial and Rational Functions
Lial13th EditionCollege AlgebraISBN: 9780136881063
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Table of contents
Chapter 4, Problem 45
Give the equations of any vertical, horizontal, or oblique asymptotes for the graph of each rational function. ƒ(x)=(x2+1)/(x2+9)
Verified step by step guidance1
Identify the rational function given: \(f(x) = \frac{x^2 + 1}{x^2 + 9}\).
Find vertical asymptotes by setting the denominator equal to zero and solving for \(x\): solve \(x^2 + 9 = 0\).
Determine if there are any real solutions to \(x^2 + 9 = 0\). If there are no real solutions, then there are no vertical asymptotes.
Find horizontal or oblique asymptotes by comparing the degrees of the numerator and denominator polynomials. Here, both numerator and denominator are degree 2.
Since the degrees are equal, the horizontal asymptote is the ratio of the leading coefficients of numerator and denominator. Write the equation of the horizontal asymptote as \(y = \frac{\text{leading coefficient of numerator}}{\text{leading coefficient of denominator}}\).
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5mKey Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Vertical Asymptotes
Vertical asymptotes occur where the denominator of a rational function equals zero and the numerator is nonzero, causing the function to approach infinity or negative infinity. To find them, set the denominator equal to zero and solve for x. These lines indicate values that the function cannot take.
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Determining Vertical Asymptotes
Horizontal Asymptotes
Horizontal asymptotes describe the behavior of a function as x approaches positive or negative infinity. For rational functions, compare the degrees of the numerator and denominator: if degrees are equal, the asymptote is the ratio of leading coefficients; if numerator degree is less, the asymptote is y=0; if greater, no horizontal asymptote exists.
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4:48Determining Horizontal Asymptotes
Oblique (Slant) Asymptotes
Oblique asymptotes occur when the degree of the numerator is exactly one more than the degree of the denominator. They are found by performing polynomial long division of numerator by denominator. The quotient (without the remainder) gives the equation of the slant asymptote, representing the end behavior of the function.
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Related Practice
Textbook Question
Graph each polynomial function. Factor first if the polynomial is not in factored form. ƒ(x)=3x4-7x3-6x2+12x+8
Textbook Question
Determine the largest open interval of the domain (a) over which the function is increasing and (b) over which it is decreasing. ƒ(x) = -3x2 + 18x + 1
Textbook Question
Several graphs of the quadratic function ƒ(x) = ax2 + bx + c are shown below. For the given restrictions on a, b, and c, select the corresponding graph from choices A–F. (Hint: Use the discriminant.) a < 0; b2 - 4ac = 0
Textbook Question
Solve each polynomial inequality. Give the solution set in interval notation. x5 + x2 + 2 ≥ x4 + x3 + 2x
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Textbook Question
Determine the largest open interval of the domain (a) over which the function is increasing and (b) over which it is decreasing. ƒ(x) = -2x2 - 8x - 7
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