Question: "drawing effect" with animate for curve given in polar equations

Hello, i would like to use the animate function to simulate the drawing of a "rose curve" ( en.wikipedia.org/wiki/Rose_curve ): the effect i would like to achieve is like this

c := 3;

animate(plot, [[cos(d*t), sin(d*t), t = 0 .. 2*Pi], -c .. c, -c .. c], d = 0 .. 1);

 

the fact is that here i'm using cartesian coordinates (though parametric, not cartesian equations), while the rose curve is given by the equation

r=cos(k*theta)

in polar coordinates... I can draw it "statically" with

k:=7;

plot(cos(k*theta), theta=0..2*Pi, coords=polar);

but i would like to obtain the "drawing effect" as for the circle. I tried converting everything in cartesian coordinates and reconducting myself to the precedent case, with parametric equations, but failed somewhere and i'm not sure where/why/how...

I have the doubt this can't be done due to some theoretical  reason underlying (which i have not still grasped). Any help appreciated

Nareto

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