If the focus of the parabola is (0,13) and the directrix is y=-13.
Let any point on the parabola = (a,b).
First, we find the distance between (a,b) and the focus (0, 13).
![\begin{gathered} \text{Distance}=\sqrt[]{(a-0)^2+(b-13)^2} \\ =\sqrt[]{a^2+(b-13)^2} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/n9uxn943e4ph3gmodg38ussgqlpct7qyru.png)
Next, find the distance between (a,b) and the directrix y=-13.

Next, equate the two expressions obtained.
![\sqrt[]{a^2+(b-13)^2}=|b+13|](https://img.qammunity.org/2023/formulas/mathematics/college/ectjacb0qnl9ww7p0r4sl7tri8m0kqxniv.png)
Square both sides.

So, the equation is:
