Polynomial

In mathematics, a polynomial is a kind of mathematical expression. It is a sum of several mathematical terms called monomials. That is, a number, a variable, or a product of a number and several variables. When an algebraic expression contains letters mixed with numbers and arithmetic, like formula_1, there is a good chance that it is a polynomial. Polynomials are taught in algebra, which is a gateway course to all technical subjects. Mathematicians, scientists and engineers all use polynomials to solve problems.
In algebra, when letters, numbers, and arithmetic symbols occur together, the understanding is that the letters stand for variables, which are either symbols of their own, numbers not yet known, or numbers that change during the course of the problem (such as time). A polynomial is an algebraic expression in which the only arithmetic is addition, subtraction, multiplication and whole number exponentiation. If harder operations are used, such as division or square roots, then this algebraic expression is not a polynomial. Polynomials are often easier to use than other algebraic expressions.
Polynomials are often used to form polynomial equations, such as the equation formula_2, or polynomial functions, such as formula_3.
Terminology.
Given a series of formula_4 numbers formula_5, a polynomial of variable formula_6 generally takes the form formula_7. The parts of a polynomial separated by plus (or minus) signs are called "terms", and the signs are themselves part of the term. 
Thus, in the polynomial "formula_1", the terms are:
If a polynomial has only one term, it is called a "monomial". Monomial are also the building blocks of polynomials. For example, formula_21 is a monomial. 
In a term, the multiplier out in front is called a "coefficient". The letter is called an "unknown" or a "variable", and the raised number after the letter is called an exponent. On a calculator and some computers, instead of putting an exponent above and to the right of the variable, the symbol ^ is used, so that the monomial above could be written as formula_22^formula_23.
A polynomial with exactly two terms is called a "binomial". A polynomial with exactly three terms is called a "trinomial". Within a term: