Question

A parabola has vertex (17, 12) and focus (17, 15). Give an equation for its directrix.

Answer 1

what's the distance between the vertex and focus?

Answer 2

vertex is "the point at the top of the arch."

Answer 3

yes... either the highest/lowest or leftmost/rightmost part of a parabola depending on what type you have....

Answer 4

example:
axis of symmetry: x = 0
vertex: (0, 0)
focus: ( 0, 1/4a )
directrix: y = – 1/4a

Answer 5

can you tell me the distance from the vertex to the focus of your problem?

Answer 6

3

Answer 7

your directrix then is 3 units opposite that of the focus...