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3 years ago

What is the directrix of a parabola with focus (4,-1) and a vertex at (4,-5)?

Mathematics

1 answer:

elena-s [515]3 years ago

5 0

Answer:

Step-by-step explanation:

The directrix is at the same distance from the vertex as the focus but on the opposite side of the vertex.

x coordinate the same for a focus and a vertex (4) means the parabola opens up or down and the directrix is parallel to the x-axis.

y coordinate of the focus greater than y coordinate of the vertex means the parabola opens up and the directrix lays below the vertex.

-1-(-5) = - 1 + 5 = 4

so: - 5 - 4 = -9 is the y coordinate of points of the directrix

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What is the directrix of a parabola with focus (4,-1) and a vertex at (4,-5)?​

What is the directrix of a parabola with focus (4,-1) and a vertex at (4,-5)?