Study Rational Functions And Zeros in AP Precalculus with focused flashcards that help you recognize the idea, recall the key rule, and apply it in practice-style prompts.
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Flashcard 1: Identify a removable discontinuity in f(x)=x−1x2−1.
Answer: Removable discontinuity at x=1. The factor (x−1) cancels from numerator and denominator.
Flashcard 2: How do you determine a hole in a rational function?
Answer: If p(x) and q(x) share a common factor. Common factors can be cancelled, creating a removable discontinuity.
Flashcard 3: Identify the hole in f(x)=x−1x2−1.
Answer: Hole at x=1. Factor x2−1=(x−1)(x+1) and cancel the common factor.
Flashcard 4: What is a zero of a rational function?
Answer: A value of x for which f(x)=0. A zero occurs when the numerator equals zero but the denominator doesn't.
Flashcard 5: What is the behavior of f(x)=x+52x as x→−5?
Answer: As x→−5, f(x)→±∞. The function has a vertical asymptote at x=−5.
Flashcard 6: What is the slant asymptote of f(x)=xx2+1?
Answer: The slant asymptote is y=x. Divide x2+1 by x using polynomial long division.
Flashcard 7: What is the horizontal asymptote of f(x)=2x+37x?
Answer: The horizontal asymptote is y=27. Equal degrees give horizontal asymptote y=27.
Flashcard 8: Identify the hole in f(x)=x−1x2−1.
Answer: Hole at x=1. Factor x2−1=(x−1)(x+1) and cancel the common factor.
Flashcard 9: Find the zeros of f(x)=x+23x2−12.
Answer: The zeros are x=2 and x=−2. Factor the numerator: 3x2−12=3(x2−4)=3(x−2)(x+2).
Flashcard 10: What is the horizontal asymptote of f(x)=2x+37x?
Answer: The horizontal asymptote is y=27. Equal degrees give horizontal asymptote y=27.
Flashcard 11: What is a zero of a rational function?
Answer: A value of x for which f(x)=0. A zero occurs when the numerator equals zero but the denominator doesn't.
Flashcard 12: What is the degree of the polynomial p(x)=3x4−2x2+1?
Answer: The degree is 4. The highest power term determines the degree of a polynomial.
Flashcard 13: Find the vertical asymptote of f(x)=x−42x+3.
Answer: Vertical asymptote at x=4. Set the denominator x−4=0 to find the vertical asymptote.
Flashcard 14: Identify the vertical asymptote of f(x)=x2−42x.
Answer: Vertical asymptotes are x=2 and x=−2. Factor x2−4=(x−2)(x+2) to find where the denominator is zero.
Flashcard 15: What are the zeros of f(x)=x+2x2−9?
Answer: The zeros are x=3 and x=−3. Factor the numerator: x2−9=(x−3)(x+3).
Flashcard 16: Find the vertical asymptote of f(x)=x−42x+3.
Answer: Vertical asymptote at x=4. Set the denominator x−4=0 to find the vertical asymptote.
Flashcard 17: What is the behavior of f(x)=x1 as x→0?
Answer: As x→0, f(x)→±∞. The function has a vertical asymptote at x=0.
Flashcard 18: What is the degree of q(x)=x3−7x?
Answer: The degree is 3. The highest power term x3 has degree 3.
Flashcard 19: What is the behavior of f(x)=x2−1x as x→1?
Answer: As x→1, f(x)→∞. The denominator (x−1) approaches 0 while numerator approaches 1.
Flashcard 20: What is the horizontal asymptote for f(x)=x+2x+1?
Answer: The horizontal asymptote is y=1. When degrees are equal, the horizontal asymptote is 11=1.
Flashcard 21: Identify a removable discontinuity in f(x)=x−1x2−1.
Answer: Removable discontinuity at x=1. The factor (x−1) cancels from numerator and denominator.
Flashcard 22: What is the horizontal asymptote for f(x)=x2+12x2?
Answer: The horizontal asymptote is y=2. Equal degrees give horizontal asymptote y=12=2.
Flashcard 23: Which term denotes values not in the domain of a rational function?
Answer: These are the poles or vertical asymptotes. Points where the denominator equals zero make the function undefined.
Flashcard 24: State the horizontal asymptote for f(x)=x+24x.
Answer: The horizontal asymptote is y=4. As x→∞, the function approaches 14=4.
Flashcard 25: What is the domain of f(x)=x2−4xx?
Answer: Domain: x=0,x=4. Factor the denominator: x2−4x=x(x−4).
Flashcard 26: Identify the horizontal asymptote of f(x)=x2−1x2+3.
Answer: The horizontal asymptote is y=1. When degrees are equal, the horizontal asymptote equals the ratio of leading coefficients.
Flashcard 27: Identify the horizontal asymptote of f(x)=x2+45x.
Answer: The horizontal asymptote is y=0. Numerator degree is less than denominator degree, so y=0.
Flashcard 28: What is the behavior of f(x)=x2−1x as x→1?
Answer: As x→1, f(x)→∞. The denominator (x−1) approaches 0 while numerator approaches 1.
Flashcard 29: State the horizontal asymptote of f(x)=x2+12x2+3.
Answer: The horizontal asymptote is y=2. Equal degrees give horizontal asymptote y=12=2.
Flashcard 30: What are the zeros of f(x)=x+2x2−9?
Answer: The zeros are x=3 and x=−3. Factor the numerator: x2−9=(x−3)(x+3).
Flashcard 31: State the condition for a vertical asymptote in a rational function.
Answer: Occurs where q(x)=0 and p(x)=0. The denominator is zero while the numerator is non-zero.
Flashcard 32: What is the behavior of f(x)=x1 as x→0?
Answer: As x→0, f(x)→±∞. The function has a vertical asymptote at x=0.
Flashcard 33: Which term describes x values making f(x) undefined?
Answer: These are the excluded values or domain restrictions. Values that make the denominator zero are excluded from the domain.
Flashcard 34: Which term describes x values making f(x) undefined?
Answer: These are the excluded values or domain restrictions. Values that make the denominator zero are excluded from the domain.
Flashcard 35: Find the zero of f(x)=x+32x−4.
Answer: The zero is x=2. Set 2x−4=0 to find where the numerator equals zero.
Flashcard 36: Find the domain of f(x)=x2−94x+1.
Answer: Domain: x=3,x=−3. Set x2−9=0 to find where the function is undefined.
Flashcard 37: Identify the horizontal asymptote of f(x)=x2+45x.
Answer: The horizontal asymptote is y=0. Numerator degree is less than denominator degree, so y=0.
Flashcard 38: Which term denotes values not in the domain of a rational function?
Answer: These are the poles or vertical asymptotes. Points where the denominator equals zero make the function undefined.
Flashcard 39: What is the degree of q(x)=x3−7x?
Answer: The degree is 3. The highest power term x3 has degree 3.
Flashcard 40: What is the horizontal asymptote for f(x)=x+2x+1?
Answer: The horizontal asymptote is y=1. When degrees are equal, the horizontal asymptote is 11=1.
Flashcard 41: Identify the vertical asymptote of f(x)=x2−255.
Answer: Vertical asymptotes at x=5 and x=−5. Factor the denominator: x2−25=(x−5)(x+5).
Flashcard 42: Find the zeros of f(x)=x+23x2−12.
Answer: The zeros are x=2 and x=−2. Factor the numerator: 3x2−12=3(x2−4)=3(x−2)(x+2).
Flashcard 43: What is the domain of f(x)=x2−4xx?
Answer: Domain: x=0,x=4. Factor the denominator: x2−4x=x(x−4).
Flashcard 44: State the horizontal asymptote of f(x)=x2+12x2+3.
Answer: The horizontal asymptote is y=2. Equal degrees give horizontal asymptote y=12=2.
Flashcard 45: State the condition for a vertical asymptote in a rational function.
Answer: Occurs where q(x)=0 and p(x)=0. The denominator is zero while the numerator is non-zero.
Flashcard 46: Find the zero of f(x)=x+1x−4.
Answer: The zero is x=4. Set the numerator x−4=0 to find where f(x)=0.
Flashcard 47: For f(x)=x−2x2−4, what is the discontinuity?
Answer: Discontinuity (hole) at x=2. Factor and cancel: (x−2) appears in both numerator and denominator.
Flashcard 48: Find the domain of f(x)=x2−94x+1.
Answer: Domain: x=3,x=−3. Set x2−9=0 to find where the function is undefined.
Flashcard 49: State the vertical asymptote of f(x)=x2−162x+1.
Answer: Vertical asymptotes at x=4 and x=−4. Factor the denominator: x2−16=(x−4)(x+4).
Flashcard 50: Identify the horizontal asymptote of f(x)=x2−1x2+3.
Answer: The horizontal asymptote is y=1. When degrees are equal, the horizontal asymptote equals the ratio of leading coefficients.
Flashcard 51: What is the domain of f(x)=x(x+3)1?
Answer: Domain: x=0,x=−3. Set x(x+3)=0 to find where the function is undefined.
Flashcard 52: What is the end behavior of f(x)=5x3+23x3+4?
Answer: As x→±∞, f(x)→53. When degrees are equal, divide leading coefficients: 53.
Flashcard 53: What is the behavior of f(x)=x+52x as x→−5?
Answer: As x→−5, f(x)→±∞. The function has a vertical asymptote at x=−5.
Flashcard 54: Identify the vertical asymptote of f(x)=x2−255.
Answer: Vertical asymptotes at x=5 and x=−5. Factor the denominator: x2−25=(x−5)(x+5).
Flashcard 55: For f(x)=x−2x2−4, what is the discontinuity?
Answer: Discontinuity (hole) at x=2. Factor and cancel: (x−2) appears in both numerator and denominator.
Flashcard 56: What is the intercept of f(x)=x−23?
Answer: Vertical intercept at (0,−23). Substitute x=0 into the function to find the y-intercept.
Flashcard 57: What is the horizontal asymptote for f(x)=x2+12x2?
Answer: The horizontal asymptote is y=2. Equal degrees give horizontal asymptote y=12=2.
Flashcard 58: Describe when a rational function has no horizontal asymptote.
Answer: When the degree of p(x) is greater than q(x). When numerator degree exceeds denominator degree, no horizontal asymptote exists.
Flashcard 59: How do you determine a hole in a rational function?
Answer: If p(x) and q(x) share a common factor. Common factors can be cancelled, creating a removable discontinuity.
Flashcard 60: Find the zero of f(x)=x+32x−4.
Answer: The zero is x=2. Set 2x−4=0 to find where the numerator equals zero.
Flashcard 61: Describe when a rational function has no horizontal asymptote.
Answer: When the degree of p(x) is greater than q(x). When numerator degree exceeds denominator degree, no horizontal asymptote exists.
Flashcard 62: What is the degree of the polynomial p(x)=3x4−2x2+1?
Answer: The degree is 4. The highest power term determines the degree of a polynomial.
Flashcard 63: What happens to f(x)=x−31 as x→3?
Answer: f(x)→±∞, vertical asymptote at x=3. As x approaches 3, the denominator approaches 0 while numerator stays 1.
Flashcard 64: What is the general form of a rational function?
Answer: f(x)=q(x)p(x) where p(x) and q(x) are polynomials. This defines a rational function as a ratio of two polynomial functions.
Flashcard 65: State the vertical asymptote of f(x)=x2−162x+1.
Answer: Vertical asymptotes at x=4 and x=−4. Factor the denominator: x2−16=(x−4)(x+4).
Flashcard 66: What is the slant asymptote of f(x)=xx2+1?
Answer: The slant asymptote is y=x. Divide x2+1 by x using polynomial long division.
Flashcard 67: State the horizontal asymptote for f(x)=x+24x.
Answer: The horizontal asymptote is y=4. As x→∞, the function approaches 14=4.
Flashcard 68: What is the y-intercept of f(x)=x+32x−5?
Answer: The y-intercept is (0,−35). Substitute x=0 to get f(0)=3−5.
Flashcard 69: Find the zero of f(x)=x+1x−4.
Answer: The zero is x=4. Set the numerator x−4=0 to find where f(x)=0.
Flashcard 70: What is the domain of f(x)=x(x+3)1?
Answer: Domain: x=0,x=−3. Set x(x+3)=0 to find where the function is undefined.
Flashcard 71: What happens to f(x)=x−31 as x→3?
Answer: f(x)→±∞, vertical asymptote at x=3. As x approaches 3, the denominator approaches 0 while numerator stays 1.
Flashcard 72: What is the general form of a rational function?
Answer: f(x)=q(x)p(x) where p(x) and q(x) are polynomials. This defines a rational function as a ratio of two polynomial functions.