From the given data :

Conic is parabola,

Eccentricity is e = 1, and

Directrix is .

So, the directrix is vertical and left of the pole.

So we can choose the equation : .

The eccentricity of a parabola is e = 1 and the distance between the pole and

the directrix is p = 1.

                  (Substitute the values : e = 1 and p = 1)

                        (Simplify)

The polar equation is .