Before: March 12, 2018 Evaluate x² + 5x for x = 4 and x = -3. Generate ordered pairs for the function y = x² + 2 with the given x-values. x y -2 -1 1 2
During: Identifying Quadratic Functions Learning Targets: I can: Identify quadratic functions (from an equation & table of values) Graph quadratic functions (using a table of values)
The function y = x² is shown below. Is this graph linear? _____
This graph is a quadratic function This graph is a quadratic function. A quadratic function is any function that can be written in the standard form: y = ax² + bx + c
Previously, you identified linear functions by finding that a constant change in x corresponded to a constant change in y.
x 1 2 3 4 y = x² This is the case for ALL quadratic functions!
“I Do” Identifying Quadratic Functions Tell whether each function is quadratic. Explain. X Y -4 8 -2 2 4
“I Do” Identifying Quadratic Functions Tell whether each function is quadratic. Explain. y = -3x + 20
“I Do” Identifying Quadratic Functions Tell whether each function is quadratic. Explain. y + 3x² = -4
“We Do” Identifying Quadratic Functions Tell whether each function is quadratic. Explain. X Y -2 4 -1 1 2
“We Do” Identifying Quadratic Functions Tell whether each function is quadratic. Explain. y + x = 2x²
“You Do” Identifying Quadratic Functions Tell whether each function is quadratic. Explain. 1. 2. y = 7x + 3 3. y – 10x² = 9 X Y -2 -9 -1 1 2 7
The graph of a quadratic function is a curve called a parabola The graph of a quadratic function is a curve called a parabola. To graph a quadratic function, generate enough ordered pairs to see the shape of the parabola. Then connect the points with a smooth curve.
“I Do” Graphing Quadratic Functions by Using a Table of Values Use a table of values to graph each quadratic function. y = 2x²
“We Do” Graphing Quadratic Functions by Using a Table of Values Use a table of values to graph each quadratic function. y = x² + 2
“You Do” Graphing Quadratic Functions by Using a Table of Values Use a table of values to graph each quadratic function. y = x² - 5
Homework: Page 526, #2 – 9 all