Quadrifolium formula of ellipse associations?



I cannot fathom the quadrifolium formula (4 petal rose) that fits the astroid. Is it the pedal curve? I tried the pedal curve parametric equations but got a different result.

I tried the parametric equation from below link:

Sorry in advance if these forum is just pertained to desmos graphing doubts. I wasn’t sure of it so posting a mathematical query on desmos.Thanks:)