Common Graphs — Question 6

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Question 6

Sketch the graph of the rational function: f(x)=x2−1x2−4f(x) = \frac{x^2 - 1}{x^2 - 4}

Instructions: Identify all intercepts, vertical and horizontal asymptotes, domain, and any removable discontinuities. Then sketch the graph based on your analysis.

Original worksheet page 1: question and worked solution for 1-10-006
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Question 6 - Solution

We are given: f(x)=x2−1x2−4=(x−1)(x+1)(x−2)(x+2)f(x) = \frac{x^2 - 1}{x^2 - 4} = \frac{(x - 1)(x + 1)}{(x - 2)(x + 2)}

Domain: x≠±2⇒(−∞,−2)∪(−2,2)∪(2,∞)x \neq \pm 2 \quad \Rightarrow \boxed{(-\infty, -2) \cup (-2, 2) \cup (2, \infty)}

Vertical Asymptotes: x=−2x = -2 and x=2x = 2

Horizontal Asymptote: Degrees of numerator and denominator are equal: y=11=y=1y = \frac{1}{1} = \boxed{y = 1}

X-intercepts: Set numerator = 0: x=±1x = \pm 1

Y-intercept: f(0)=−1−4=14f(0) = \frac{-1}{-4} = \frac{1}{4}

See the diagram in the original worksheet below.

Original worksheet page 2: question and worked solution for 1-10-006

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