4.2 Graph Quadratic Functions in Vertex or Intercept Form To graph quadratic functions in vertex or intercept form To write equations in standard form

Vertex Form Characteristics: The vertex is (h, k) + - + - Characteristics: The vertex is (h, k) The axis of symmetry is x = h a controls the width of the graph and if opens up or down

Graph y = -2(x-3)2+4 2 1 2 -4 -14 Vertex: (3, 4) Fill out a chart. Remember, you pick the x value and solve for y. x y 2 1 2 -4 -14

Intercept Form

Graph y = 2(x + 3)(x – 1) Steps: 1.Plot x intercepts 2. Find axis of symmetry 3. Find the coordinates of vertex 4. Plot some pts 5. Connect the dots What makes y = 0?...-3 & 1 -3+1 = -2 then divide in ½ = -1 Plug -1 into equation for x and solve for y. Find more pts Pick x and solve for y.

To Standard Form Goal: Make the equations look like ax2 + bx + c Example: Write f(x) = 4(x-2)2 +1 in standard form = 4(x - 2)(x - 2) + 1 = 4(x2 – 4x + 4) +1 = 4x2 – 16x + 16 + 1 = 4x2 – 16x + 17

Homework: Pg 249 1 – 37 Every other odd, 53