WARM UP What is the x-coordinate of the vertex? 1.y = -2x 2 + 8x – 5 2.y = x 2 + 3x -2 4

WARM UP What is the x-coordinate of the vertex? 1.y = -2x 2 + 8x – 5 2.y = x 2 + 3x -2 3

WARM UP What is the x-coordinate of the vertex? 1.y = -2x 2 + 8x – 5 2.y = x 2 + 3x -2 2

WARM UP What is the x-coordinate of the vertex? 1.y = -2x 2 + 8x – 5 2.y = x 2 + 3x -2 1

What is the x-coordinate of the vertex? 1.y = -2x 2 + 8x – 5 2.y = x 2 + 3x -2 WARM UP 0

A quadratic function is a function that can be written in the standard form y = ax 2 + bx + c Every quadratic function has a U-shaped graph called a parabola. The parabola opens up if the value of a is positive. The parabola opens down if the value of a is negative. 9.4 Graphing Quadratic Functions

The vertex is the highest or lowest point on a parabola. The vertical line passing through the vertex that divides the parabola into two symmetric parts is called the axis of symmetry. The two symmetric parts are mirror images of each other. 9.4 Graphing Quadratic Functions

SKETCHING GRAPHS 1.Find the vertex 2.Does the graph open up or down? 3.Create a table with the vertex in the middle and two values to the left and right. 4.Plot the points and connect the graph, label the vertex and draw the line of symmetry. 9.4 Graphing Quadratic Functions

SKETCHING GRAPHS y = x 2 – 5x Graphing Quadratic Functions x y

SKETCHING GRAPHS y = -x 2 + 2x Graphing Quadratic Functions x y

SKETCHING GRAPHS y = 2x 2 – 3x Graphing Quadratic Functions x y

YOU’RE CERTIFIED! Page 523 #s Graphing Quadratic Functions