Overview
1.
Find the vertex, focus, directrix, and focal width of the parabola.
x2 = 12y (1 point)
Vertex: (0, 0); Focus: (3, 0); Directrix: x = 3; Focal width: 3
Vertex: (0, 0); Focus: (0, 3); Directrix: y = -3; Focal width: 12
Vertex: (0, 0); Focus: (3, 0); Directrix: y = 3; Focal width: 48
Vertex: (0, 0); Focus: (0, -3); Directrix: x = -3; Focal width: 48
2.
Find the vertex, focus, directrix, and focal width of the parabola.
x = 3y2 (2 points)
Vertex: (0, 0); Focus:
; Directrix: x =
; Focal width: 12
Vertex: (0, 0); Focus:
; Directrix: x =
; Focal width: 0.33
Vertex: (0, 0); Focus:
; Directrix: x =
; Focal width: 0.33
Vertex: (0, 0); Focus:
; Directrix: y =
; Focal width: 12
3.
Find the standard form of the equation of the parabola with a vertex at the origin and a focus at (0, -7). (1 point)
y =
x2
y2 = -7x
y =
x2
y2 = -28x
4.
Find the standard form of the equation of the parabola with a focus at (0, 8) and a directrix at y = -8. (2 points)
y =
x2
y2 = 8x
y2 = 32x
y =
x2
5.
Find the standard form of the equation of the parabola with a focus at (7, 0) and a directrix at x = -7. (2 points)
y =
x2
x =
y2
-28y = x2
y2 = 14x
6.
A building has an entry the shape of a parabolic arch 96 ft high and 18 ft wide at the base, as shown below.