Math Problem Statement

Question 2(Multiple Choice Worth 3 points) (Rational Functions' Vertical Asymptotes and Holes MC)

The rational function r is defined as r of x equals the fraction with numerator x squared minus 5 x minus 14 and denominator x squared plus 9 x plus 14. Which of the following statements describes the behavior of r ?

The graph of r has an intercept at x = 2. The graph of r has a hole at x = –7 and a vertical asymptote at x = –2. The graph of r has a hole at x = –2 and a vertical asymptote at x = –7. The graph of r has zeros at x = 2 and x = 7 because r (2) = r (7) = 0.

Solution

To analyze the rational function r(x)=x25x14x2+9x+14r(x) = \frac{x^2 - 5x - 14}{x^2 + 9x + 14}, we need to identify its zeros, holes, and vertical asymptotes.

  1. Finding Zeros: The zeros of the function occur when the numerator is zero: x25x14=0x^2 - 5x - 14 = 0 Factoring gives: (x7)(x+2)=0(x - 7)(x + 2) = 0 So, x=7x = 7 and x=2x = -2 are the zeros.

  2. Finding Holes and Vertical Asymptotes: We look for values that make the denominator zero: x2+9x+14=0x^2 + 9x + 14 = 0 Factoring gives: (x+7)(x+2)=0(x + 7)(x + 2) = 0 So, the denominator is zero at x=7x = -7 and x=2x = -2.

    Since x=2x = -2 is also a zero of the numerator, there is a hole at x=2x = -2. The remaining factor x+7=0x + 7 = 0 in the denominator creates a vertical asymptote at x=7x = -7.

Summary:

  • Zeros: x=7x = 7 and x=2x = -2
  • Hole: x=2x = -2
  • Vertical Asymptote: x=7x = -7

Conclusion:

The correct statement is: The graph of r has a hole at x=2x = -2 and a vertical asymptote at x=7x = -7.

Would you like further details or explanations on this? Here are some questions for consideration:

  1. How do you find holes in rational functions?
  2. What is the significance of vertical asymptotes?
  3. Can you explain the difference between a zero and a hole?
  4. How do you graph rational functions with holes and asymptotes?
  5. What happens to the function's value as it approaches the asymptote?

Tip: Always factor both the numerator and denominator to clearly identify zeros, holes, and vertical asymptotes.

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Math Problem Analysis

Mathematical Concepts

Rational Functions
Asymptotes
Zeros

Formulas

Factoring quadratic equations

Theorems

Identifying holes and vertical asymptotes in rational functions

Suitable Grade Level

Grades 9-12