This document defines key concepts related to quadratic functions and their graphs:
1) A quadratic function is a second-degree polynomial function of the form f(x) = ax^2 + bx + c, where a cannot be 0.
2) The graph of a quadratic function is called a parabola, which has a vertex and may open upward or downward depending on the sign of a.
3) The axis of symmetry is the vertical line through the vertex that divides the parabola into two equal parts.
2. AXIS OF SYMMETRY
The vertical line
through the vertex that
divides the parabola
into two equal parts.
3. DIRECTION OF OPENING OF A
PARABOLA
Can be determined from the
value of a in f(x) = ax族 + bx + c.
If a > 0, the parabola opens
upward; if a < 0, the parabola
opens downward.
4. DOMAIN OF A QUADRATIC FUNCTION
The set of all possible values
of x. Thus the domain is the
set of all real numbers.
6. QUADRATIC FUNCTION
A second-degree function of
the form f(x) = ax族 +bx + c where
a, b, and c are real numbers
and a 0. This is a function
which describes a polynomial of
degree 2.
7. RANGE OF A QUADRATIC FUNCTION
Consists of all y greater than or equal to
the y-coordinate of the vertex if the
parabola opens upward. Consists of all y
less than or equal to the y-coordinate of
the vertex if the parabola opens
downward.
8. VERTEX
The turning point of the parabola or the
lowest or highest point of the parabola.
If the quadratic function is expressed in
standard form y = a(x-h)族 + k, the vertex
is the point (h, k)