Objectives: Be able to graph a quadratic function in vertex form Be able to write a quadratic function in vertex form (2 ways)
Vertex Form of a Quadratic Reflection over x-axis if a is negative, vertical stretch (a > 1) or shrink (a < 1) Horizontal translation (opposite of what you see!) *The vertex of the parabola is (h, k) and the axis of symmetry is x = h. Vertex Form of a Quadratic Equation: Vertical Translation
xy a. Vertex (horiz. and vert. translation) b. Axis of symmetry c. Table Point Vertex Corresp. d. Ask: Correct reflection? Correct stretch or shrink? Graphing Equations in Vertex Form
a. Vertex (horiz. and vert. translation) b. Axis of symmetry c. Table Point Vertex Corresp. d. Ask: Correct reflection? Correct stretch or shrink? xy Try this one…
Ex 4) Write the equation for the following parabola in vertex form: y = a(x – h) 2 + k Vertex Form from Graph
Ex 4) Write the equation for the following parabola in vertex form: y = a(x – h) 2 + k Vertex Form from Graph
Ex5) Write y = 2x x + 7 in vertex form. a. Find the x-coordinate of the vertex (h): b. Find the y-coordinate of the vertex (k): c. Substitute a, h, and k into vertex form: Vertex Form from Standard Form
Ex5) Write y = –7x 2 – 70x – 169 in vertex form. a. Find the x-coordinate of the vertex (h): b. Find the y-coordinate of the vertex (k): c. Substitute a, h, and k into vertex form: Vertex Form from Standard Form