** Axis of Symmetry ** -
The line which divides the parabola into two symmetrical halves. In the equation for the parabola
*y* = *a*(*x* - *h*) + *k*
, the axis of symmetry is
*x* = *h*
.

** Completing the Square ** -
A process by which we add and subtract a constant to create a perfect square trinomial within an equation and transform the equation of the form
*y* = *ax*
^{2} + *bx* + *c*
into an equation of the form
*y* = *a*(*x* - *h*)^{2} + *k*
.

** Discriminant ** -
In the quadratic equation, the expression
*b*
^{2} - 4*ac*
. The discriminant determines the number of solutions to a quadratic equation, or the number of
*x*
-intercepts of a quadratic function.

** Parabola ** -
The shape of the graph of

*y* = *a*(*x* - *h*)^{2} + *k*
.

Graph of
*y* = *x*
^{2}

** Quadratic Equation ** -
An equation of the form
*ax*
^{2} + *bx* + *c* = 0
, where
*a*≠ 0
, and
*a*
,
*b*
, and
*c*
are real numbers.

** Quadratic Formula ** -
Given a quadratic equation

*ax*
^{2} + *bx* + *c* = 0
, the solutions are given by the equation

*x* =
.

** Quadratic Function ** -
A function of the form
*y* = *ax*
^{2} + *bx* + *c*
, where
*a*≠ 0
, and
*a*
,
*b*
, and
*c*
are real numbers.

** Vertex ** -
In the equation
*y* = *a*(*x* - *h*)^{2} + *k*
, the point
(*h*, *k*)
-- the minimum point in a parabola that opens upward, or the maximum point in a parabola that opens downward.