Polynomials Flashcards
an algebraic expression where the exponents of its variables are whole numbers.
Polynomials
What expressions are NOT polynomials?
- Expressions with fractional or decimal exponents in the variable are not polynomials
For example, 4x1/2+ 2y3is not a polynomial since one of its variables, which is x, has a fractional exponent of ½.
- Expressions with negative exponents in the variable are not polynomials
For example, 2a-3b – 5a2b3+ ab is not a polynomial since one of its variables, which is a, has a negative exponent which is – 3.
- Expressions with variables in the denominator are not polynomials
For example, 3x – 2⁄y is not a polynomial since it has a variable (which is y) in the denominator.
How about x + y⁄2? Is this a polynomial?
Although 2 is the denominator, 2 is not avariable. This means that x + y⁄2 can be considered a polynomial since it has no variable in the denominator.
Why does a variable in the denominator disqualify an algebraic expression as a polynomial?
As per thenegative exponent rule, if a variable is raised to a negative exponent, we should put that variable in the denominator so that the variable will now have a positive exponent.
If a variable is in the denominator, then it implies that before the negative exponent rule was applied, the variable had a negative exponent in the numerator.
We know that a negative exponent in the variable makes an expression a non-polynomial. This is the reason why variables in the denominator make an expression non-polynomial.
- Expressions with variables under the radical sign are not polynomials
Square root (√) and cube root (∛) are some of the examples of radical signs.
As an example, let’s consider the expression √x – y. Since it has a variable (which is x) that is under the radical sign, then √x – y is not a polynomial.
How about √2 + x? Is this a polynomial?
Look at the radical sign. Note that 2 is inside the radical sign. 2 is a constant and not a variable. Thus, we can consider √2 + x as a polynomial
____in a polynomial consists of a number multiplied by a variable with a whole number exponent. The constant part is also a term of the polynomial.
Term
Example:Determine the terms in 3x2+ 5y – 2xz
Solution:The terms in the given polynomials are 3x2, 5y, and 2xz.
Two or more terms are ____ terms if their variables and exponents (of the variables) are the same
Like terms
Example 1:Are 2xz and 5xz like terms?
Solution:Yes, because these terms have the same variables (which arexandz).
Example 2:Which of the following does not belong to the group of like terms: 5a2b, -4a2b, 3a2b2, and 9a2b.
Solution:3a2b2does not belong to the group because it has a different exponent for its variable b.
the highest exponent of the variable of a polynomial.
Degree of a polynomial
Example:What is the degree of the polynomial 3k^7– 5k^2+ k – 9?
Solution:The highest exponent of the variable in the polynomial is 7. Thus, the degree of the polynomial is 7.
A polynomial with 1 term
Monomial
A polynomial with 2 terms
Binomial
A polynomial with 3 terms
Trinomial
A polynomial with 4 terms and above
Multinomial
an expression that has one term. This means that a constant, a variable, or a product of a constant and a variable with an exponent is a monomial. Examples: 4, a, 5x, -9y2, and 4a2b.
Monomial
an expression that has two terms.Examples: x + 2, 2y + z, 4ab – 3b2, and p2q – 3.
Binomial
an expression that has three terms. Examples: x2+ 2xy + y2, 3x – y + 5, and 6x3y + y – 9
Trinomial
an expression with more than three terms. Examples: a + 2ab + 3abc + 4bcd and 4x2yz + xy3z – xyz2+ xyz + 1.
Multinomial
Degree 0
Constant
Degree 1
Linear
Degree 2
Quadratic
Degree 3
Cubic