Correct question is ;
Given the equation of the parabola x² = -36y
The focus of the parabola is:
Answer:
Option C - Focus = (0,-9)
Step-by-step explanation:
The equation of the parabola is:
x² = -36y
Thus, y = - x²/36
Using the vertex form,
y = a(x − h)² + k, to determine the values of a, h, and k.
We will have;
y = (-1/36)(x − 0)² + 0
Thus,
a = - 1/36
h = 0
k = 0
The distance (p) from the vertex to a focus of the parabola is gotten by using the following formula.
p = 1/4a
So, p = 1/(4*(-1/36))
p = - 1/(1/9)
p = -9
Now, The focus of a parabola can be found by adding p to the y-coordinate k if the parabola opens up or down.
Focus is (h, k+p)
Plugging in the relevant values, we have;
Focus = (0, (0 + (-9))
Focus = (0,-9)
