In the xy-plane, the graph of a rational function f has a vertical asymptote at x=−5. Which of the following could be an expression for f(x) ?(A) 2(x−5)(x−5)(x+5)(B) (x−1)(x+5)(x−4)(x+5)(C) (x−5)(x+2)(x+1)(x+5)(D) (x−3)(x+5)(x−5)(x−3)
Q. In the xy-plane, the graph of a rational function f has a vertical asymptote at x=−5. Which of the following could be an expression for f(x) ?(A) 2(x−5)(x−5)(x+5)(B) (x−1)(x+5)(x−4)(x+5)(C) (x−5)(x+2)(x+1)(x+5)(D) (x−3)(x+5)(x−5)(x−3)
Identify Vertical Asymptote: Identify the characteristic of a vertical asymptote in a rational function. A vertical asymptote occurs where the denominator of a rational function is zero, but the numerator is not zero at the same x-value.
Examine Option (A): Examine option (A) to see if it has a vertical asymptote at x=−5.The denominator of option (A) is 2(x−5), which is zero when x=5, not x=−5. Therefore, it cannot have a vertical asymptote at x=−5.
Examine Option (B): Examine option (B) to see if it has a vertical asymptote at x=−5. The denominator of option (B) is (x−1)(x+5), which is zero when x=−5. However, the numerator also has a factor of (x+5), which would cancel out the (x+5) in the denominator, eliminating the vertical asymptote at x=−5.
Examine Option (C): Examine option (C) to see if it has a vertical asymptote at x=−5. The denominator of option (C) is (x−5)(x+2), which is zero when x=5, creating a vertical asymptote at x=5. Since we are looking for a vertical asymptote at x=−5, this option is not correct.
Examine Option (D): Examine option (D) to see if it has a vertical asymptote at x=−5. The denominator of option (D) is (x−3)(x+5), which is zero when x=−5. The numerator is (x−5)(x−3), which does not cancel out the (x+5) in the denominator. Therefore, this function has a vertical asymptote at x=−5.
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