Solving for the Discontinuities of Rational Equations
Review: 3 Types of Discontinuities Vertical Asymptotes (VAs) Horizontal Asymptotes (HAs) Holes
Degree The greatest exponent of an expression Examples: f(x) = x 6 – x f(x) = x 4 – x 9 + x 11 – x f(x) = 8x + 4 f(x) = 7
Important Vocabulary, cont.:
Multiplicity
Multiplicity, cont.
Horizontal Asymptotes Investigation Remember: The horizontal asymptote describes how the graph behaves AT ITS ENDS Look for the graph to taper to the same y-value on both ends of the graph Look for dashed, horizontal lines We DON’T DRAW dashed lines on the X-AXIS or the Y-AXIS!!!
Horizontal Asymptotes Depend on the degree of the numerator and the denominator Degree of Numerator < Degree of Denominator HA: y = 0 Degree of Numerator = Degree of Denominator HA: ratio of leading coefficients Degree of Numerator > Degree of Denominator HA: doesn’t exist
Examples
Solving for Vertical Asymptotes Examples
Your Turn: Solve for the VA
Solving for Vertical Asymptotes and Holes 1. Always factor the numerator and the denominator 1 st ! 2. Identify linear factors in the denominator 3. Figure out where the linear factors in the denominator occur the most to decide if you have a vertical asymptote or a hole 4. Set the linear factors from step 2 equal to zero and solve for x.
Solving for Vertical Asymptotes and Holes, cont. Occur in Denominator Only? Occur Most in Denominator? Occur = # of Times in Numerator and Denominator? Occur Most in Numerator? VA Set factor equal to 0 and solve for x. VA Set factor equal to 0 and solve for x. Hole Set factor equal to 0 and solve for x. Hole Set factor equal to 0 and solve for x. Does the linear factor:
Example #1
Example #2
Example #3
Example #4
Your Turn: Complete problems 1 – 8 on the Solving for Vertical Asymptotes and Holes Practice handout. BE PREPARED TO SHARE YOUR ANSWERS!!! Complete problems 9 – 14.