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Write an equation for a parabola with focus (2,4) and directrix x = 10.

User Mounir Bkr
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Answer:

To find the equation of a parabola given its focus and directrix, we can use the definition of a parabola.

The standard form of the equation of a parabola with its focus at (h, k + p) and directrix y = k - p is:

(x - h)^2 = 4p(y - k)

In this case, the focus is (2, 4) and the directrix is x = 10. Since the directrix is a vertical line, we have a horizontal parabola.

Comparing the given values to the standard form, we have:

h = 2

k + p = 4

k - p = 10

From the equations k + p = 4 and k - p = 10, we can solve for k and p by adding the two equations together:

(k + p) + (k - p) = 4 + 10

2k = 14

k = 7

Substituting the value of k into either equation, we can solve for p:

7 + p = 4

p = 4 - 7

p = -3

Now we have the values of h, k, and p. Substituting them into the standard form equation, we get:

(x - 2)^2 = 4(-3)(y - 7)

Simplifying further:

(x - 2)^2 = -12(y - 7)

Thus, the equation of the parabola with focus (2, 4) and directrix x = 10 is (x - 2)^2 = -12(y - 7).

User Bigstylee
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