1. 4.2 STANDARD FORM OF A
QUADRATIC FUNCTION
Part 1: Properties of Standard Form and Graphing
using Standard Form
2. QUADRATIC FUNCTIONS
Vertex Form:
Standard Form is another way to write the
equation of a quadratic function.
Standard form is:
Both forms can represent the same function.
Vertex form makes it easy to identify the
vertex and other information about the graph.
Standard form is easier to put into a graphing
calculator and is more “formal”.
3. PROPERTIES OF STANDARD FORM
The graph of is a parabola.
If a > 0, the graph opens up. If a < 0, the graph
opens down.
The axis of symmetry is the line
The x – value of the vertex is and the y –
value of the vertex is
The y – intercept is (0, c)
4. EXAMPLE: IDENTIFY THE VERTEX, AXIS OF
SYMMETRY, THE MAXIMUM OR MINIMUM VALUE, AND
THE RANGE OF THE PARABOLA
5. EXAMPLE: IDENTIFY THE VERTEX, AXIS OF
SYMMETRY, THE MAXIMUM OR MINIMUM VALUE, AND
THE RANGE OF THE PARABOLA
6. GRAPHING A FUNCTION IN STANDARD FORM
1. Identify a, b, and c
2. Identify and sketch the axis of symmetry,
3. Identify and plot the vertex,
4. Identify and plot the y – intercept, (0, c)
5. Use the axis of symmetry and y – intercept to plot
the reflected point
6. Sketch the parabola
