Here, the equation of parabola is: (-36y)=x^2
The standard form of parabola is:
(X-h)^2=4p(y-k).
According to given equation, vertex = (0,0) and p = -9
This a vertical parabola opening down, because p = -9 here.
Therefore ditectrix will be y= -9
Answer: 11+5=16
Step-by-step explanation: 14, 15, 16, 17 and 18