Recall that a linear equation in one variable is of the form , where and are constants and .
A quadratic equation has an (-squared) term. ("Quadratum" is Latin for square.)
The general quadratic equation in standard form looks like
, . . . . where .
If we want to find the or 's that work, we might guess and substitute and hope we get lucky, or we might try one of these four methods:
We can solve graphically by equating the polynomial to instead of to , we get an equation whose graph is a parabola. The -intercepts of the parabola (if any) correspond to the solutions of the original quadratic equation.