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Introduction to Rational Equations. 2 Types of Functions. Continuous Discontinuous. Continuous. Continuous. Keeps going No breaks in graph Smooth. Discontinuous. Discontinuous. Stops Graph has breaks or holes. Examples. Continuous Graphs → Polynomials
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2 Types of Functions • Continuous • Discontinuous
Continuous • Keeps going • No breaks in graph • Smooth
Discontinuous • Stops • Graph has breaks or holes
Continuous Graphs → Polynomials • Discontinuous Graphs → Rational Equations
Your Turn: Be Prepared to Share!!! • Complete problems 1 – 6 on the Introduction to Rational Equations handout • Remember, you need to: • Classify the graph as either continuous or discontinuous • Classify the graph as either a polynomial or a rational equation • Justify your reasoning!!!
Sharing Activity • I will gently throw the ball to a student. • That student answers the first question. • Then the student will gently throw the ball to another student. • That student answers the next question. • Repeat until we’ve answered all the questions. Say the student’s name before you throw him/her the ball!
Polynomial • Polygamy • Polytheism • Polydactyl • Polyglot • Monomial • Binomial • Trinomial
Polynomials, cont. • A polynomial is an algebraic expression that can be written in the form anxn + an-1xn-1 + … + a2x2 + a1x1 + a0 • An equation or an expression with a single variable raised to (usually many) powers • All exponents are whole numbers • an ≠ 0 (Leading Coefficient ≠ 0)
Polynomial Examples • Generally a long list of variables • f(x) = x4 – 4x3 + 2x2 – 3x + 11 • f(x) = x11 + 7x5 – 4x3 + x – 12 • But we can also have a short list of variables • f(x) = x5 + x • f(x) = x2 – 1 • Or even no variables at all! • f(x) = 10 • f(x) = ½
Rational Equations, cont. • Rational equations are fractions in which both the numerator and the denominator are polynomials • We don’t need variables in the numerator, but we must have them in the denominator!!!
Polynomials vs. Rational Equations 7. f(x) = x8 – 7x2 + 4 8. f(x) = 11 9. 10. 11.
Your Turn: Be Prepared to Share!!! • Complete problems 12 – 17 on the Introduction to Rational Equations handout. • Remember, you need to: • Classify the equation as either a polynomial or a rational equation. • Justify your reasoning
Compare – Contrast – Summarize Graphic Organizer Continuity → Continuous or Discontinuous
Discontinuous Graphs Discontinuities Rational Graphs
*Discontinuities • Discontinuity – a point or a line where the graph of an equation has a hole, a jump, a break, or a gap • Affect the shape, domain and range of an equation
Discontinuities, cont. • Three major types of discontinuities: • Vertical Asymptotes • Horizontal Asymptotes • Holes Asymptotes Point (Removable) Discontinuity
Lines that the graph approaches but (almost) never crosses Represented by a dashed line Not part of the equation We don’t draw them if they happen on either the x-axis or the y-axis Type of Discontinuities – Asymptotes
Vertical Asymptotes (1st Column) • Occur when the numerator is a non-zero # and the denominator equals zero • Can never be crossed • Always in the form x = • Abbreviated VA
Vertical Asymptotes, cont. Hand Drawn Calculator Drawn The calculator doesn’t draw the asymptotes!!!!
Experiment • Graph in your graphing calculator
Occur when the degree of the denominator is ≥ the degree of the numerator Ex. Can be crossed when |x| is very small Describes the end behavior of a rational equation Always in the form y = Abbreviated HA Horizontal Asymptotes (2nd Column)
Horizontal Asymptotes, cont. Hand Drawn Calculator Drawn The calculator doesn’t draw the asymptotes!!!!
Gaps in the graph at a single point Occurs when Always in the form x = Represented by an open circle (or hole) in the graph Point (Removable) Discontinuities – Holes (3rd Column)
Holes, cont. Hand Drawn
Graphing calculators have difficulty showing removable discontinuities ****Check the table for errors! Graphing Calculators and Holes
Example #1 • x-int = • y-int = • VA: • HA: • Holes:
Example #2 • x-int = • y-int = • VA: • HA: • Holes:
Your Turn: • Complete problems 1 – 6 on the Identifying Features of Rational Equations Practice handout. • Don’t answer the domain and range questions!
Discontinuities and Domain and Range • Discontinuities affect the domain and range of a rational equation • Vertical Asymptotes → Domain • Horizontal Asymptotes →Range • Holes → Domain and Range
Domain: Range: Example 1:
Domain: Range: Example 2:
Your Turn: • Answer the domain and range questions for problems 1 – 6 on the Identifying Features of Rational Equations Practice handout.
Homework • Complete problems 1 – 6 on the Identifying the Features of Rational Equations Homework handout.
Exit Ticket • Identify the following features of the graph on the right: • x-int. = • y-int. = • VA: • HA: • Holes: • Domain: • Range: