1. Algebra II Section 8-2 Parabolas (the dreaded lesson)

2. Conic Sections

3. Find a point equidistant from (2, 3) and the line y = -1 Distance from (x, y) to (2, 3)=Distance from (x, y) to (x, -1) This is a parabola!

4. Properties of Parabolas All incoming parallel rays are reflected to the same point (focus). This is true for light, sound, radio, …

5. Vertex = (h, k) Focus Line segment through the focus Parallel to the directrix Name : Latus Rectum. a ky Directrix 4 1 

6. Sideways? See chart on page 422 Mythbusters Illusion

7. Parabola A Parabola B Focus of A Focus of B

8. Find the Focus, Vertex, Directrix, Axis of Sym., Length of the L.R. y = -2x 2 – 20x + 9 Put in Vertex Form y = -2(x + 5) 2 + 59 Focus = (-5, 58.875) Vertex = (-5, 59) Directrix y = 59.125 Length of L.R. = 0.5 Axis of Sym. x = -5

9. Page 423 # 1-41 odd