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Find the equation of the parabola with its focus at (3,4) and its directrix y = 0.

User Michielodc
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2 Answers

7 votes

Answer:

y = 1∕8(x – 3)2 + 2

Explanation:

User Rubin Porwal
by
5.2k points
2 votes

Answer:

Equation of parabola: 8*(y - 2) = (x - 3)^2

or

y = (1/8)*(x - 3)^2 + 2

Explanation:

focus at (3,4) and its directrix y = 0.

Focus equation: (h, k + c) = (3, 4)

Directrix equation y = k - c = 0

so h = 3, k + c = 4, k - c = 0

Solve the system : k + c = 4 and k - c = 0

add the equations together: k + c + k - c = 4 + 0

2k = 4

k = 2

so k + c = 4, 2 + c = 4, c = 2

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

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

8*(y - 2) = (x - 3)^2

User Simon Hibbs
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5.4k points