For a conic with a focus at the origin, if the directrix is
![y=\pm p](https://img.qammunity.org/2023/formulas/mathematics/college/5t0hmubv9ughi5ot5jktr13fe0kdgki365.png)
where p is a positive real number, and the eccentricity is a positive real number e, the conic has a polar equation
![r=(ep)/(1\pm e\sin\theta)](https://img.qammunity.org/2023/formulas/mathematics/college/dc99yak4x5h8igxs0zk0odt178o372rdwz.png)
if 0 ≤ e < 1 , the conic is an ellipse.
if e = 1 , the conic is a parabola.
if e > 1 , the conic is an hyperbola.
In our problem, our equation is
![r=(5)/(1+5\sin\theta)](https://img.qammunity.org/2023/formulas/mathematics/college/k9re82ji7rt8io94z4nvo27b2urj25mc7y.png)
If we compare our equation with the form presented, we have
![\begin{cases}e={5} \\ p={1}\end{cases}](https://img.qammunity.org/2023/formulas/mathematics/college/uyiza7oemqzy51wncf6kbtrceojummw2hn.png)
Therefore, the directrix is
![y=1](https://img.qammunity.org/2023/formulas/mathematics/high-school/dy87pp1e3lz28ku95s9s4tv5bvbrg0dkd1.png)