Table of contents
- 0. Review of Algebra4h 16m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 6m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 19m
- 10. Combinatorics & Probability1h 45m
5. Rational Functions
Introduction to Rational Functions
Problem 53
Textbook Question
In Exercises 45–56, use transformations of f(x)=1/x or f(x)=1/x^2 to graph each rational function. h(x)=1/x2 − 4
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1
Identify the base function: The base function here is \( f(x) = \frac{1}{x^2} \).
Determine the transformation: The given function is \( h(x) = \frac{1}{x^2} - 4 \). This represents a vertical shift of the base function downward by 4 units.
Analyze the asymptotes: The vertical asymptote remains at \( x = 0 \) since the transformation does not affect the x-values. The horizontal asymptote, originally at \( y = 0 \), shifts to \( y = -4 \) due to the vertical shift.
Consider the domain and range: The domain of \( h(x) \) is all real numbers except \( x = 0 \). The range is all real numbers except \( y = -4 \).
Sketch the graph: Start by plotting the vertical asymptote at \( x = 0 \) and the horizontal asymptote at \( y = -4 \). Then, sketch the curve of \( \frac{1}{x^2} \) shifted downward by 4 units, ensuring it approaches the asymptotes appropriately.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Rational Functions
Rational functions are expressions formed by the ratio of two polynomials. They can exhibit unique behaviors such as asymptotes, intercepts, and discontinuities. Understanding the structure of rational functions is essential for analyzing their graphs, particularly how they behave near vertical and horizontal asymptotes.
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Intro to Rational Functions
Transformations of Functions
Transformations involve shifting, reflecting, stretching, or compressing the graph of a function. For the function h(x) = 1/x^2 - 4, recognizing that the '-4' indicates a vertical shift downward is crucial. Mastery of transformations allows for the manipulation of basic functions like f(x) = 1/x or f(x) = 1/x^2 to create new graphs.
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Domain & Range of Transformed Functions
Asymptotes
Asymptotes are lines that a graph approaches but never touches. For rational functions, vertical asymptotes occur where the denominator is zero, while horizontal asymptotes describe the behavior of the function as x approaches infinity. Identifying these asymptotes is vital for accurately sketching the graph of h(x) = 1/x^2 - 4.
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Introduction to Asymptotes
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