A quadratic equation is one which includes a term with an exponent of 2, for example, formula_30, and no term with higher exponent. The name derives from the Latin "quadrus", meaning square. In general, a quadratic equation can be expressed in the form formula_85, where is not zero (if it were zero, then the equation would not be quadratic but linear). Because of this a quadratic equation must contain the term formula_86, which is known as the quadratic term. Hence formula_87, and so we may divide by and rearrange the equation into the standard form