A polynomial is an expression of one variable in the form a_{n}x^{n} + a_{n-1}x^{n-1} + ^{ ... } + a_{2}x^{2} + a_{1}x + a_{0}, where a_{0}, a_{1},…, a_{n} are
real numbers with a_{n}≠ 0 and n is a positive integer. Many real-life
situations are easily modeled by polynomial functions. Some of the most
familiar are quadratic functions, which are
functions of the form f (x) = ax^{2} + bx + c.
Other polynomial functions are also commonly seen in mathematical models. In
the following sections we'll study the general form of polynomials, what a
polynomial function looks like, and how to find the roots of a given
polynomial function. The roots of a polynomial function are the values of x
for which the function equals zero. In a related topic, we'll take a look at
rational functions, which are functions that can be written as a quotient of
two polynomials. After an in-depth look at polynomial functions, they will be
easy to deal with in calculus.