The polar equation will be [tex]r=\dfrac{4}{1+cos\theta}[/tex]
A polar equation is any equation that expresses the relationship between r and theta, where r is the distance between the pole (origin) and a point on a curve, and theta is the counterclockwise angle formed by a point on a curve, the pole, and the positive x-axis.
From the equation, we are told that
The Eccentricity: e = 1
The Directrix is y = 4
Generally, the polar equation for e = 1 and y = + c is mathematically represented as
[tex]r =\dfrac{e\times c}{1+ecos\theta}[/tex]
[tex]r =\dfrac{1\times 4}{1+1\times cos\theta}[/tex]
[tex]r=\dfrac{4}{1+cos\theta}[/tex]
Therefore the polar equation will be [tex]r=\dfrac{4}{1+cos\theta}[/tex]
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