4 Real Zeros of Polynomial Functions.notebook · 4 Real Zeros of Polynomial Functions.notebook 9...

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4 Real Zeros of Polynomial Functions.notebook 1 August 07, 2012 Real Zeros of Polynomial Functions

Transcript of 4 Real Zeros of Polynomial Functions.notebook · 4 Real Zeros of Polynomial Functions.notebook 9...

Page 1: 4 Real Zeros of Polynomial Functions.notebook · 4 Real Zeros of Polynomial Functions.notebook 9 August 07, 2012 2. If, k is a factor of . 3. k an ä Uses of the Remainder in Synthetic

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Real Zeros of Polynomial Functions

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Real Zeros of Polynomial Functions

The Division Algorithm:

• f(x) and d(x) are polynomials d(x) ≠0

• Degree of d(x) ≤ f(x)

• If r(x)=0, then d(x) divides evenly into f(x).

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Long Division. . . 

Are you smarter than a fifth grader?

EX#1: Let’s look at this rule with simple numbers.

Find the quotient, remainder, dividend and divisor of 763÷3

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Long Division vs. Synthetic Division

EX#2: Divide using Long Division

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EX#3: Divide using Synthetic Division

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THE REMAINDER AND FACTOR THEOREMS

If a polynomial f(x) is divided by x – k , the remainder is r = f(k)

EX#4: Use the remainder theorem to evaluatewhen

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EX#5: Is a factor of?

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EX#6: Verify that and are factors of ind all the zeros of f.

Using The Remainder Theorem

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2. If, k is a factor of .

3.    k an

Uses of the Remainder in Synthetic Division

The remainder r, obtained in synthetic division ofby provides the following:

1. The remainde r gives the value of at k

That is,

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The Rational Zeros Theorem

If is a polynomial of degree indescending order then it is possible to make an organized list of potential rational numbers to aid in inding zeros of the function.

Possible Rational = Zeros

EX#7: Find the rational zeros of:

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More Rational Zeros and Real Zeros

EX#8: Find the rational zeros of:

Ex#9: Find all the real zeros of

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Modeling

EX#10: Find a polynomial function with leading coeficient 2 that has the given degree and zeros. Degree3,with zerosat

EX.#11: Find the cubic function with the given table of values. Check with a grapher.

x –2 1 2 3y 0 24 0 0