Circles and conic sections

Find the equation of a parabola that passes through point (2, 1) with vertex (0, 0).

• y = -¹/₄x² - 2
• y = -¹/₄x² + 2
• y = ¹/₄x² + 2
• y = 1¹/₄x² - 2

Convert the equation

f(x) = x² - 12x + 40

into vertex form

• f(x) = (x + 6)² - 4

• f(x) = (x + 6)² + 4

• f(x) = (x - 6)² - 4

• f(x) = (x - 6)² + 4

Find the vertex if the focus is at (9,0) and the directrix is at x=-9

• (-9,0)

• (0,9)

• (0,0)

• (0,-9)

What is p for this parabola?

 $(x-6)^2=20(y-1)$  

• p=20

• p=4

• p=5

• p=6

The parabola y = 1/2 (x + 4)² - 3 will

• open down

• open up

The parabola y = x² - 2x + 4 will

• open up

• open down

A satellite dish is in the shape of a parabola and has a width of 2 meters and a height of 1 meter. The equation of the parabola is given by y = 0.5x^2 - x + 1, where y is the height in meters and x is the horizontal distance in meters. Graph the parabola on a coordinate plane.

• y = 0.5x^2 - 2x + 1

• y = 0.5x^2 - x + 1

• y = 2x^2 - x + 1

• y = 0.5x^2 + x + 1

Find the focus, and directrix of the parabola: x² = 28y

• Focus: (0,7) Directrix: y= -7

• Focus: (7,0) Directrix: y=7

• Focus: (0,-7) Directrix: x= -7

• Focus: (7, 0) Directrix: x=7

A parabola is upside-down when a is:

• negative

• positive

• 0

• infinite

What is "a" in the equation:
(y-9)² = -40(x+4)

• - 10
• 10
• - 40
• 40