1. Vertex form (standard form) for the equation of a parabola
y = a(x – h)2 + k x = a(y – k)2 + h
Vertex: (h, k) Vertex: (h, k)
Line of symmetry: x = h Line of symmetry: y = k
2. Graph x = 2y2 + 8y + 9
x = (2y2 + 8y )+9
x = 2(y2 + 4y + 4) + 9 - 8
x = 2(y + 2)2 + 1
Vertex: (1, -2)
Axis of symmetry: y = -2
Opens to the right
10. y = ¼ (x + 3)2 + 2
vertex: (-3, 2)
axis of symmetry:
x = -3
a=¼
distance from vertex
1_
to focus = 4(¼) = 1
Length of latus
distance from vertex rectum:
to directrix = 1
1 = 4 units
¼