Multiple each number I think
Because if it is a decrease in change, it will be told as a "fall" in change ;')
To solve this problem you must apply the proccedure shown below:
1. The vertex i at <span>(0, 36) and a focus at (0, 39), then you have:
a=36
a^2=1296
2. The directrix is:
y=a^2=c
c=39
y=1296/39
</span>y=432/13<span>
Therefore, the answer is the option D, which is: </span><span>D. y=± 432/13</span>
