Question

Derive the equation of the parabola with a focus at (−5, 5) and a directrix of y = -1.

Answer 1

A) f(x) = −one twelfth (x − 5)2 + 2

B) f(x) = one twelfth (x − 5)2 + 2

C) f(x) = −one twelfth (x + 5)2 + 2

D) f(x) = one twelfth (x + 5)2 + 2

Answer 2

Do you think this parabola is a vertical or a horizontal one? How would you know?
Note that the vertex of a parabola is located exactly half-way between the focus and the directrix. Please find the coordinates of the focus.

Answer 3

I'd suggest that you draw a graph, to help you visualize this situation.