Define a polynomial with real coefficients.

In the polynomial $f(x)=a_{n} x^{n}+a_{n-1} x^{n-1}+\cdots+a_{1} x+a_{0}$,

$a_{n} x^{n}, a_{n-1} x^{n-1}, \cdots, a_{1} x$, and $a_{0}$ are known as the terms of the polynomial and $a_{n}, a_{n-1}, \cdots, a_{1}$ and $a_{0}$ are their real coefficients.

For example, $p(x)=3 x-2$ is a polynomial and 3 is a real coefficient