What is the equation of a limacon?

1 Answer
Apr 27, 2016

r2=a2cos2θ.
The graph is the fallen eight, looking like the symbol ...

Explanation:

For the double loop of r2=a2cos2θ,cos2θ0.

So, the range for θ[0,2π] excludes (π4,3π4) and

(5π4,7π4), Here, cos2θ<0...