Focus and Directrix of Parabolic Equations

The focus is always inside the parabola.

• true
• false

When the x-part is squared, the parabola opens up or down.

• True

• False

The focus is at (2,0) and the vertex is at (-4,0).  What is the equation of the parabola?

• y² = 24(x+4)
• (y+4)² = -12x
• x² = 16(y+4)
• (x+4)²  = -20y

What is the point inside the parabola 'p' units from the vertex?

• vertex
• focus
• directrix
• axis of symmetry

Given this directrix and vertex, what would the equation of the parabola be?

• (y-2)² = 12(x-1)
• (y-2)² = 6(x-1)
• (x-1)² = 12(y-2)
• (x-1)² = 6(y-2)

A parabola is the set of all points equidistant from the vertex and the directrix.

• true

• false

The sign of the 'p' value can help you determine if the graph opens upward, downward, left, or right.

• True

• False

If the directrix is y = 4 and the focus is at

(3, 0), the vertex of the parabola is:

• (3, 0)

• (3, 2)

• (3.5, 0)

• (0, 3.5)

All parabolas with a vertical directrix open the left or right.

• true
• false

If the directrix is vertical, the parabola will be vertical.

• true
• false