The equation is x2 = -16y
Here we know that the coefficient of y is negative.
So, the parabola opens downwards.
On comparing this equation with x2 = -4ay, we get,
-4a = -16
a =\( \dfrac{-16}{-4}\)
= 4
Thus, co-ordinates of the focus = (0,-a) = (0,-4)
Since, the given equation involves x2, the axis of the parabola is the y-axis.
The equation of directrix, y =a, then,
y = 4
Length of latus rectum = 4a = 4(4) = 16
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