The given equation is x2=−16y
Here, the coefficient of y is negative.
Hence the parabola opens downwards.
On comparing this equation with x2=−4ay
−4a=−16
⇒a=4
∴ Coordinates of the focus =(0,−a)=(0,−4)
Axis of the parabola is the y-axis i.e x=0
Equation of directrix y=a i.e., y=4
Length of latus rectum =4a=16