3.6 Graph Rational Functions Part II
Remember Rational functions have asymptotes To find the vertical asymptote, set the denominator = 0 and solve for x x-5 = 0 x=5
To find horizontal asymptote Eliminate any term that involves an x and solve for y y = 3
Using Asymptotes to Graph Draw dotted lines for asymptotes Pick values for x based on the asymptotes and solve for y
GUIDED PRACTICE for Examples 1, 2 and 3 Graph the function and identify its domain and range. Compare the graph with the graph of y = 1 x ANSWER 1. y = – 4 x Domain: all real numbers except 0 Range: all real numbers except 0 The graph is a vertical stretch of y = that is then reflected in the x -axis. 1 x
GUIDED PRACTICE for Examples 1, 2 and 3 2. y = 1 x – 4 1 x Domain: all real numbers except 0 Range: all real numbers except – 4 The graph is a vertical translation (of 4 units down) of the graph y =. ANSWER Graph the function and identify its domain and range. Compare the graph with the graph of y = 1 x
GUIDED PRACTICE for Examples 1, 2 and 3 3. y = 1 x x Domain: all real numbers except – 5 Range: all real numbers except 0 The graph is a horizontal translation (of 5 units left) of the graph y =. Graph the function and identify its domain and range. Compare the graph with the graph of y = 1 x ANSWER
GUIDED PRACTICE for Examples 1, 2 and 3 y = 1 x Describe how the graph of is related to the graph of y =. 1 x The graph of y = is a horizontal translation (of 3 units left) of the graph of y =. x x 1 ANSWER
SOLUTION EXAMPLE 4 Graph y = + k a x – h Graph y = – 3. 2 x + 1
GUIDED PRACTICE for Example 4 5. Graph y = x – 5 ANSWER
GUIDED PRACTICE for Example 4 6. For which function is the domain all real numbers except –3 and the range all real numbers except 7 ? A. y = x – 3 B. y = – 7. 2 x – 3 C. y = x + 3 D. y = – 7. 2 x + 3 ANSWER C. y = x + 3