*Completing the square* is a technique used to convert an expression of the form , where , , and are constants, to an expression of the form , where and are both constants.

The *leading term* of a polynomial expression is its highest degree term. If a polynomial is written in standard form, the leading term should be the first term. The coefficient of the leading term is called the *leading coefficient* of the expression. For the polynomial , the leading term is , and the leading coefficient is .

The *tangent line* to a curve at a certain point is a straight line that touches the curve at only that point and has the same slope as the curve at that location.