Completing The Square

A technique that can solve any quadratic equation, by factoring into a squared binomial. Not quite as impressive as pulling a rabbit out of a hat, but still a neat trick.

Complex Numbers

Numbers with both a real and imaginary component, of the form a + bi.

Discriminant

The expression b² – 4ac. It's called the discriminant because it helps us discriminate between real and imaginary solutions to quadratic equations. If it's positive, our quadratic has two real roots. If it's negative, it's got two complex roots. If it's zero, we'll only see one real root.

I (Math)

The imaginary number, equal to .

Imaginary Numbers

Numbers that contain i, of the form bi.

Parabola

The graphical representation of a quadratic equation. A smooth, continuous curve that points in one direction.

Quadratic Equation

A polynomial equation of the form y = ax² + bx + c.

Quadratic Formula

A formula for finding the roots of a quadratic equation:

Quadratic Function

A relation where the input (x) is related to the output (f(x)) by a quadratic equation: f(x) = ax² + bx + c.

Vertex

The single maximum or minimum value of a parabola.