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Polynomials. Lecture 3C Pre AP & GT Precalculus. Agenda. Degrees Humps End Behavior Zeroes. Degrees. **A, B, C, D, E, F, G are all constant coefficients. Other Names. Zeroes…. (definition) A zero of a polynomial is any value x such that
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Polynomials Lecture 3CPre AP & GT Precalculus
Agenda • Degrees • Humps • End Behavior • Zeroes
Degrees **A, B, C, D, E, F, G are all constant coefficients
Zeroes… • (definition) A zero of a polynomial is any value x such that • Find zeroes is a very important and practical problem • Quadratic Equation
A teacher’s motto… • Engage… • Enlighten… • Empower
Zeroes… • Reflection: Is it possible to find a Cubic Equation? • Yes, first found by Scipione del Ferro • HOW: • Depressing the cubic… • Substitute: • Substitute some more: • Quadratic Equation
The Posers Cardano Tartaglia
Cubic EquationSummary Method (Lots of substitution) • Notice the imaginary numbers showing up in x2 and x3 • Notice x1, apparently a cubic always has at least one real root
Quartic Equation • Found by Cardano’s student Ferrari • Published in Cardano’sbook Ars Magna • How messy is the quartic equation?
Quintic Equation Niels Abel Paolo Ruffini Solution to the general Quintic is Impossible!
Smooth or Not Smooth? Smooth Not Smooth This cannot be a polynomial • A polynomial is always smooth
My Humps • If p(x) is an degree n polynomial, then it will has (at most) n-1 humps • If a polynomial has n-1 humps then it is of the nth-degree (at least) • What degree? • 5, 6, 7 ….
My humps, my humpsName the polynomial: Cubic: 2 humps Quintic: 4 humps
Odd Degree End Behavior Positive Leading Coefficient Negative Leading Coefficient Increases Left & Right Decreases Left & Right
Even Degree End Behavior Positive Leading Coefficient Negative Leading Coefficient Decreases LeftIncreases Right Increases LeftDecreases Right
What could it look like?Humps and End Behavior… Septic? • How many humps? • One less so 6 • End behavior? • Increases both left and right
What is a Bump? • Mathematically, a bump is a change of concavity (officially known as a point of inflection) • A bump is equivalent to 2 humps • Example: y=x3 • How many humps do you expect? • 2 but instead you only get1 bump
A note about humps…. • What degree? • Minimum: 16th degree (a bump is two humps: think y=x3)
Finding Zeroes on your calculator • Graph Function…Adjust window so you can see all humps • Draw graph on your paper • Estimate zeroes and the find exact values via Calc (2nd trace), option 2 • Zeroes will be covered in greater depth next week
Challenge Problem (Due Tomorrow) • If where a, b, and c, are constants and then what is • 2 Points for the first correct solution to me (after school) • 1 Point for each correct solution afterwards • 1 Point for presenting it to your class (first taker each period)
Homework • Pg 148 V1,3,5,7 • Pg 148 #1-8(A) • Pg 149 #16,20 • Pg 149 #28-40(4th) • Pg 152 99-101