WARM-UP: Graphing Using a Table x y = 3x  2 y -2 y = 3(-2)  2 -8 y = 3(-1)  y = 3(0)  y = 3(1)  y = 3(2)  2 4 GRAPH. y = 3x  2

WARM-UP: Graphing Using a Table xy = x 2 y -2y = (-2) 2 4 y = (-1) 2 1 0y = (0) 2 0 1y = (1) 2 1 2y = (2) 2 4 GRAPH. y = x 2

Graph. y = -x 2 - 2x - 4 x y -2y = -(-2) 2 – 2(-2) – 4-4 y = -(-1) 2 – 2(-1) – 4-3 0y = -(0) 2 – 2(0) – 4-4 1y = -(1) 2 – 2(1) – 4-7 2y = -(2) 2 – 2(2) – 4-12

Graphing a Quadratic using a Table Chapter 5.1

Graphs of Quadratics The graph of a quadratic function is a Parabola. (U-shape up or down) Example: y = 2x 2 - 8x + 6 The highest or lowest point on a graph of a quadratic function is called the VERTEX. The AXIS OF SYMMETRY is the vertical line through the vertex.

Finding the Zeros of a Quadratic Function The x-intercepts of the graph of a quadratic function are called ZEROS. y = x 2 – 8x + 12 When x = 2, y = 0 or When x = 6, y = 0 At x-intercepts, y = 0 x 2 – 8x + 12 = 0 (x – 2)(x – 6) = 0

Finding the Vertex of a Parabola To find the x-coordinate of the Vertex, use the formula: Find the y-coordinate of the Vertex by substituting the x you just found into the original quadratic function.  b_ 2a

Graphing a Quadratic Function using a Table For Quadratic Functions: y = ax 2 + bx + c 1.Find the Vertex 2.Plot the Vertex and Draw the Axis of Symmetry 3.Choose TWO x’s to Left of the Axis of Symmetry for your TABLE and calculate the y-coordinates 4.Plot the 2 points from your table AND plot symmetric matches to the right of axis of symmetry. 5.Connect the dots to draw your parabola.