A *parabola* is a curve shaped almost like a . In this course, we will just look at parabolas that open either upward or downward on the coordinate plane. As a result, the *axis of symmetry*, the line that divides the parabola equally in half, for each parabola we talk about will be a vertical line. Parabolas of this sort have equations of the form , where , , and are constants and is not equal to .

In this class, we will say that the equation of a parabola is in *standard form* if it is written in the form , where , , and are constants and is not equal to .

When we *factor* a polynomial, we break it down so that it is written as a product of factors. In this course, we will say that a polynomial is *fully factored* or *completely factored* when it is written as the product of factors with integer coefficients and none of its factors can be factored any further. For example, is fully factored, whereas is not because we could instead write it as .

A *quadratic equation* is an equation of the form , where , , and are constants and is not equal to .