lesson 9.1 I CAN . . . -identify parts of a parabola. -find the axis of symmetry & vertex. lesson 9.1

vocabulary Highest point on graph Lowest point on graph Word Definition Picture Parabola Vertex Axis of Symmetry Maximum Minimum Shape of quadratic equation Point where direction of graph changes (curve) Imaginary line where parabola can be folded in half Highest point on graph Lowest point on graph

vocabulary value of “a” is positive value of “a” is negative Word Definition Picture Up Down Roots Other Names: value of “a” is positive value of “a” is negative solutions where parabola touches x-axis zeroes x-intercepts

quadratic standard form

Labeling a parabola Draw the axis of symmetry. Put a dot at the vertex. Identify if the parabola is opening up or down. Label the vertex as a max or min. Write the coordinates of the parabola across the x-axis. Example 1: Example 2: Vertex: Max or Min? _____________ Vertex: Max or Min? _____________ Open up or down? _______________ Open up or down? _______________ Coordinates across x-axis: ____________ Coordinates across x-axis: ____________

Axis of symmetry Means the “opposite of b”

Find the equation for the axis of symmetry and vertex of: Example #3: Find the equation for the axis of symmetry and vertex of: a b c x = ______ 4 = ____ 4 = 2 x = 2 2 (1) 2 y = (2)2 – 4(2) + 11 y = 7 (2, 7)

Axis of symmetry & vertex Find the axis of symmetry and the vertex for each quadratic equation. a b c x = ______ 12 = ____ 12 = –3 x = –3 2 (–2) –4 y = –2(–3)2 – 12(–3) – 18 y = 0 (–3, 0)

Find the axis of symmetry for the following two parabolas. Are you a master?? Find the axis of symmetry for the following two parabolas. 1) 2) a b c

Today’s assignment 9.1 Worksheet