Answer:
Explanation:
Given that,
To find the standard form of the equation of the parabola with a focus at (0, 9) and a directrix y = -9.
What is a parabola?
A parabola is a cross-section cut out of the cone and represented by an equation
Focus of the prabola = (h , k + F ) = (0, 9)
Since the directrix, y = -9
F = -9
k + F = 9
k = 0
Vertex of the parabola = (h, k )
= (0, 0)
Standard equation of the parabola
( y - k ) = 4a (x - h)²
( y - 0 ) = 4a (x - 0)²
y = 4 * 9 x²
y = 36 x²
Thus, the required expression for the parabola with focus at (0, -9) and a directrix y = 9 is y = 36x².