Page 44 - Math Course 3 (Book 1)

Quadratic Equations
Mo. 2

Lesson 1 Key Concept

KEY CONCEPTS: Quadratic Function
1. Graph quadratic functions.
2. Find the equation of the axis of symmetry Words A quadratic function can be
described by an equation of the
and the coordinates of the vertex of a form y = ax + bx + c, where a ≠ 0.
2
parabola.
Models y y

MO. 2 - L1a 0 x 0 x

Quadratic Functions:
Graphing y

Vocabulary A-Z 0 x

Let us learn some vocabulary y = x 2

quadratic function Let’s Begin

A function f is a quadratic function if
2
f(x) = ax + bx + c, where a, b, and c are
real numbers, with a ≠ 0.
Graph Opens Upwards

A quadratic function can be written in the form
2
y = ax + bx + c. Example

2
Use a table of values to graph y = x – x – 2.
Graph these ordered pairs and connect them with
a smooth curve.

Answer

x y
parabola –2 4

The graph of a quadratic function is called a y = x² – x – 2 –1 0
parabola.
0 –2
y 1 –2

y y 2 0
0
x 3 4
0 0
x x
y = x 2
if a > 0, the parabola if a < 0, the parabola
opens upward opens downard
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