Question

Find the equation of the parabola with vertex (2, 1) and focus (1, -1).
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Answer 1

Answer:

Step-by-step explanation:

The graph is a parabola with vertex at (0,0) that opens to the right. One standard form of the equation is

x+=+%281%2F%284p%29%29y%5E2

where p is the distance from the vertex to the focus.

In your example, the equation in that form is

x+=+%281%2F16%29y%5E2

which means p=4 and the focus is at (4,0).

Then, since this focal chord cuts the parabola at (4,8), the focal chord is a vertical line passing through (4,0) and (4,8); so the equation of the focal chord is x=4.