Converting specific equations from Polar to Cartesian These different equations are given in Polar and my goal is to plot them in Cartesian coordinate system:


*

*$r = \cos(4φ)$

*$ φ = \dfrac r {r-1}$, $r > 1$


I am aware of:


*

*$x = r \cos( φ )$

*$y = r \sin( φ )$

*$r^2 = x^2 + y^2\\$


However I cannot figure out how to use these traits properly, and I am not able to find any relatable examples.
Any hints how should I approach this?

*

*Use $x=r\cos\varphi=\cos 4\varphi\cos\varphi$ and similar for $y$ 

*Use $x=r\cos\varphi=r\cos\dfrac{r}{r-1}$ and similar for $y$.

