an introduction to polynomials copyright scott storla 2015

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Coefficient Variable termConstant term Copyright Scott Storla 2015

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Copyright Scott Storla 2015

An Introduction to Polynomials

Copyright Scott Storla 2015

Some Vocabulary for Polynomials

Copyright Scott Storla 2015

3 5x

Coefficient

Variable term Constant term

Copyright Scott Storla 2015

Notice a polynomial is a sum. You should think of

23 4x x as

2 13 1 4x x

Definition – Polynomial A polynomial in x is a single term, or a sum of terms, where each term is a variable term or a constant. Every variable term has a coefficient, the variable x, and an exponent of x that is a natural number.

Example: 32 3 5x x

Copyright Scott Storla 2015

One term 3 monomialk

Special names for the number of terms.

Two terms 3 7 binomialk

Three terms 3 7 trinomialk n

Copyright Scott Storla 2015

11 14n

14n

1. Write the polynomial as a sum with all coefficients and exponents explicit.

2. Discuss the polynomial in both general and specific terms.

Copyright Scott Storla 2015

1. Write the polynomial as a sum with all coefficients explicit.

2. Discuss the polynomial in both general and specific terms.

11 5y

5y

Copyright Scott Storla 2015

34 28 7 5 1a a a

The degree of a term

The degree of the entire polynomial is the same as the degree of the term with the largest exponent.

The degree of a polynomial

For each variable term use the exponent to decide on the degree of the term.

34 28 7 5 1a a a

Copyright Scott Storla 2015

Standard Form

The terms of the polynomial are written in decreasing order of degree from left to right.

3 25 7 2 Not in standard formb b b 3 27b 2 5 Standard formb b

3 21 5 7 2b b b 3 27 2 1 5b b b

To write a polynomial in standard form we imagine all operations are addition and all coefficients are explicit, then we use the commutative property to rearrange the terms, last we rewrite all explicit coefficients implicitly.

3 25 7 2b b b

3 27b 2 5b b

Copyright Scott Storla 2015

Standard Form

In practice people rearrange the terms of a polynomial “in their head”.

4 2 32 15 5x x x x

Write each polynomial in standard form.

4 3 25 2 15x x x x

7 3 9 29 12 15y y y y y

9 7 3 29 15 12y y y y y

5 7 3 8 2 47 5 8 3 6 4 2k k k k k k

8 7 5 4 3 23 5 7 2 8 4 6k k k k k k

Copyright Scott Storla 2015

1. Write the polynomial in standard form

2. Discuss the polynomial in general terms.

3. Discuss the polynomial term by term.

23 2x x 22 3x x

5 6 26 5 4 5 6n n n n 6 5 25 6 6 4 5n n n n

315 15y315 15y

Copyright Scott Storla 2015

1. Write the polynomial in standard form

2. Discuss the polynomial in general terms.

3. Discuss the polynomial term by term.

5 7 3 8 2 47 5 8 3 6 4 2k k k k k k 8 7 5 4 3 23 5 7 2 8 4 6k k k k k k

Copyright Scott Storla 2015

Multivariable or “mixed” terms

With multivariable terms the degree of the term is the sum of the individual exponents. We don’t actually add the exponents.

A second degree termab42 A fifth degree termxy

2 3 23 z A seventh degree termx y

Copyright Scott Storla 2015

Multivariable or “mixed” terms

2 2 2a is often rewritten but is left alone.b ab a b

2 2 2 22 2 is usually rewritten 2 2y x x y

2

2

Even though 7 and 5 are both second degree terms, they are usually written in

the order 5 7 .

xy x

x xy

For standard form, terms of equal degree can be written in any order but often decisions are made using alphabetical order.

Copyright Scott Storla 2015

1. Write the polynomial in standard form

2. Discuss the polynomial in general terms.

3. Discuss the polynomial term by term.

2 2 2 23 2xy x y x y 2 2 2 22 3x y x y xy

2 412 2 2 15j k jk k 4 215 12 2 2k j k jk

2 3 2 37 2 5ab a a b b 3 2 2 32 5 7a a b ab b

Copyright Scott Storla 2015

Some Vocabulary for Polynomials

Copyright Scott Storla 2015

Adding and Subtracting Polynomials

Copyright Scott Storla 2015

Terms are like if, in general, they’re counting the same sized unit.

Only like terms can be added or subtracted.

Copyright Scott Storla 2015

Like Polynomial Terms

6 , 11 Are like termsy y

26 , 11 Are liken ot t r s e mk k

5 56 , 11 Are like termsc c

Polynomial terms in one variable are like if the variable has the same exponent. Constant terms are also considered like.

Copyright Scott Storla 2015

Decide on the like terms

35 7t t t

2 2 24 2 7x x x x

3 2 3112 8 72y y y y

3 25 4 1k k k

Copyright Scott Storla 2015

32x

2 3 3 24 3 4 2x x x x

22x 4

Simplify

Copyright Scott Storla 2015

Simplify

4 3 4 2x x

5x 1

6 9 4 2 5y y y

0y 33

3 3 4 11 7 8x x x x

x 0x

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3 2 2 36 9 4 2 5y y y y

Simplify

2 24 3 4 2x x

7 4 4 7 7 45 7 4 4 3p p p p p p

3 2 2 3 2 33 3 4 11 7 8x x x x x x x

2 3 2 32 5 4 9y y y y y

3 23 7y y

25 1x

46p

x

3 24 6y y y

Copyright Scott Storla 2015

2 15 4 2 11x xy xy x

Simplify

2 23 4 8x y yx yx xy

2 2 2 2 2 26 2x y y x xy x y

2 2 2 2 2 2 2 2 24 4 7 7 15 5i j i j j i i j ji i j j i

2 2 2 2 2 2 23 5 6 3 9 14a b ba a b b b a

3 9 13xy x

22 4x y xy

2 2 2 24x y x y xy

2 2 22i j ij

2 2 2 220 2 9 3a b a b b

Copyright Scott Storla 2015

Adding and Subtracting Polynomials

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