The monomial 7x^3 is called a monomial of third degreeor a monomial of degree 3,
because the variable occurs three times as a factor.
- 5 x^2 is a monomial of degree 2. Because the variable occurs two times
as a factor: x^2 xx. - 8 a^4 is a monomial of degree 4. Because the variable occurs four times
as a factor: a^4 aaaa. - is a monomial of degree 5. Because the variable occurs five times
as a factor: m^5 mmmmm.
We define the degree of a polynomial by considering the degrees of each of its
terms.
Degree of a Polynomial
The degree of a polynomialis the same as the degree of its term with largest
degree.
For example,
- x^2 5 xis a binomial of degree 2, because the degree of its term with largest
degree (x^2 ) is 2. - 4 y^3 2 y7 is a trinomial of degree 3, because the degree of its term with
largest degree (4y^3 ) is 3. - is a trinomial of degree 4, because the degree of its term with
largest degree (3z^4 ) is 4.
1
2 z^3 z
(^4) 2 z 2
1
2
m^5
A-6 Appendix II Polynomials
EXAMPLE (^2) Find the degree of each polynomial:
a. 2 x 4 b. 5 t^3 t^4 7 c. 3 9 z 6 z^2 z^3
StrategyWe will determine the degree of each term of the polynomial.
WHYThe term with the highest degree gives the degree of the polynomial.
Solution
a.Since 2 xcan be written as 2 x^1 , the degree of the term with largest degree is
- Thus, the degree of the polynomial 2 x4 is 1.
b.In 5t^3 t^4 7, the degree of the term with largest degree (t^4 ) is 4. Thus, the
degree of the polynomial is 4.
c. In 3 9 z 6 z^2 z^3 , the degree of the term with largest degree (z^3 ) is 3. Thus,
the degree of the polynomial is 3.
Self Check 2
Find the degree of each
polynomial:
a. 3 p^3
b. 17 r^4 2 r^8 r
c. 2 g^5 7 g^6 12 g^7
Now TryProblems 13, 15, and 17
Evaluate polynomials.
When a number is substituted for the variable in a polynomial, the polynomial takes
on a numerical value. Finding this value is called evaluating the polynomial.
2
EXAMPLE (^3) Evaluate each polynomial for x3:
a. 3 x 2 b. 2 x^2 x 3
StrategyWe will substitute the given value for each xin the polynomial and
follow the order of operations rule.