x -4 -2 -1 -½ ½ 1 2 4 8-4 LEARNING GOALS 8.4.1 Graph rational functions. 8.4.2 Transform rational functions by changing parameters. 8.4.3 Identify vertical and horizontal asymptotes, and holes The parent function for the family of rational functions is: Its graph is called a _______________. They are characterized by two separate branches and two asymptotes. Domain: Range: x -4 -2 -1 -½ ½ 1 2 4 A _____________________ function is a function whose graph has one or more gaps or breaks. Example: Hyperbolas A _____________________ function is a function whose graph has no gaps or breaks. Examples: Lines, Parabolas, Logarithmic Curves, Exponential Functions 8.4 Pg. 1
Example 1: Transforming Rational Functions Using the graph of as a guide, describe the transformation and graph each function. A. B. 8.4 Pg. 2
Example 2: Determining Properties of Hyperbolas Using the graph of as a guide, describe the transformation and graph each function. C. Example 2: Determining Properties of Hyperbolas A. Identify the asymptotes, domain, and range of the function Sketch the graph: Vertical asymptote: Domain: Horizontal asymptote: Range: 8.4 Pg. 3
ZEROS B. Identify the asymptotes, domain, and range of the function Vertical asymptote: Sketch the graph: Domain: Horizontal asymptote: Range: C. Identify the asymptotes, domain, and range of the function Vertical asymptote: Sketch the graph: Domain: Horizontal asymptote: Range: ZEROS What is a “zero”? What does it look like graphically? What has to be true about a fraction to make it = 0 Example 3: Finding Zeros Identify the zeros of f(x). A. B. 8.4 Pg. 4
Example 3 Continued: Finding Asymptotes Vertical asymptotes are written as: X = _____ They are found by factoring the denominator and setting it equal to zero. Horizontal asymptotes are written as: Y = ______ They are found by looking at the degree of the numerator and denominator using the chart below. Degree of numerator & denominator N > D N < D N = D Type of horizontal asymptote None y = 0 y = Identify both the vertical and horizontal asymptotes of the function. A. B. C. D. 8.4 Pg. 5
Example 4: Graphing Rational Functions with Holes When a functions numerator = ____ and denominator = ____ for the same x value the graph may have a ____________. HOLE: NO HOLE: Example 4: Graphing Rational Functions with Holes Identify holes in the graph of f(x). Then graph. A. B. 8.4 Pg. 6