## Precalculus: Concepts Through Functions, A Unit Circle Approach to Trigonometry (3rd Edition)

Polynomials consist of one or more monomials and have the form: $$a_nx^n+a_{n-1}x^{n-1}+...+ a_1x+a_0$$ where $x$ is the variable, $a_n$ is the leading coefficient, and $n$ is a non-negative integer called the degree. We see that the given expression $\frac{3x^2+2x-1}{x^2+x+1}$ is not a polynomial because it can not be written as a sum of monomials in the form above.