Discriminant: In a quadratic equation is the expression inside the radical: b² - 4ac.

Function: A relation of the type that has exactly one value in the domain (independent variable) matching a value in the range (dependent variable).

Function notation: A function written with the symbol f(x) instead of y. It is read as f of x.

Quadratic equation: An equation of the form

ax² + bx + c = 0 where a, b, and c are real numbers and a is different from zero.

Quadratic formula: If ax² + bx + c = and a is different from zero then the quadratic formula is given in terms of a, b, and c.

Quadratic function: Any function in the form of

f(x) = ax² + bx + c where a is different from zero. The graph is a parabola and the largest exponent is 2.

Solution or root: The value that makes an equation a true statement, a root refers particularly to the value of x for which y = 0, this value is also the x-intercept of the graph.

Vertex: The lowest point for a parabola that opens up (minimum); the highest point for a parabola that opens down (maximum).

Vertex form of a quadratic function: The vertex form of a quadratic function is: f(x) = a(x-h)² + k. The vertex coordinates are (h,k).

Zeros of a function: The solutions for the equation of the function when this equal to 0. The roots, also known as the x-intercepts.