Department of Mathematics |
Basic Algebra by Example Series |
Key Concept: Know the basic meaning and properties of a polynomial
so as to perform basic operations with
polynomials
Skills to Learn
1. Know how to identify polynomials (monomials, binomials, and trinomials)
2. Know how to add and subtract polynomials
3. Know how to multiply and divide polynomials
4. Know how to find the Conjugate Binomials
Definitions of Polynomials
Polynomials
(a monomial or the sum of monomials) with whole number exponents |
||
Monomials
(a product of one or more variables) |
Binomials
(a polynomial with 2 terms) |
Trinomials
(a polynomial with 3 terms) |
-5x3 (degree 3, coefficient -5) | 2x5 + 3x2
(degree is 5) |
2x5y2 + 3x2
+ 5x
(degree is 7) |
15x3y (degree 4, coefficient 15) | -3x3 - 4y4
(degree is 4) |
(degree is 5) |
3a2bc2 (degree 5, coefficient 3) | 3x2y4 + 3xy
(degree is 6) |
3x2y2 + 5xy2 +
2x
(degree is 4) |
Add and Subtract Polynomials
Example: Add
Remove parentheses and group like terms
|
Example: Add
Remove parentheses and group like terms
|
Example: Subtract
Remove parentheses and group like terms
|
Example: Subtract
Remove parentheses and group like terms
|
Multiply Polynomials
Foil method of multiplication
(a + b)(c + d) = ac +ad +bc +bd |
Example: Multiply
Remove parentheses and use commutative property
|
Example: Multiply
Expand (distributive property)
(no like term so finish) |
Example: Multiply
Foil
(then combine xy terms) (then factor out 2)
|
Example: Multiply
Foil
|
Dividing Polynomials
Example: Divide Move exponents in denominator to numerator
|
Example: Divide
|
Example: (text book gives better
example using
sign)
Note: So
Note: So Answer is |
Example: (text book gives better
example using
sign)
Note: So
Note: So Answer is |
Conjugate Binomials
The conjugate
binomial: the conjugate of (a + b) = (a -
b) and the conjugate of
(a - b) is (a + b)
Example: the conjugate of |
Used to rationalize denominators (also numerators)
Conjugate Binomial
Example: Rationalize The conjugate of and So So |
Example: Rationalize denominator for Conjugate of So |
Example: Rationalize the numerator
Conjugate:
So
So |
Example: Rationalize the denominator
Conjugate of So Or |