Question

The vertex of a parabola is (6,2), and the equation of its directrix is y = 4.
What is the equation of this parabola in standard form?

(y−2)2=8(x−6)

(x−6)2=−8(y−2)

(y−2)2=−8(x−6)

(x−6)2=8(y−2)

Answer 1

Answer:

Step-by-step explanation:

If you plot the vertex and the directrix, you'll see that the directrix is a horizontal line above the vertex. That means that the parabola opens upside down and has the standard equation:

$(x-h)^2=-4p(y-k)$ where h and k are the coordinates of the vertex and p is the number of units between the directrix and the vertex. From the vertex we determine that h = 6 and k = 2. And by counting, we determine that p = 2. Filling in the equation then gives us:

$(x-6)^2=-4(2)(y-2)$ and simplifying just a tiny bit will get us what we need:

$(x-6)^2=-8(y-2)$ which is the second choice down.

Answer 2

Answer:

(y - 2)² = -8(x - 6) I took the quiz

Step-by-step explanation: