1. 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

2. 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

4. 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

5. Intercept Form

6. 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.

7. 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
= 4x2 – 16x + 17

8. Homework:
Pg – 37 Every other odd, 53