r(t)=(abs(t-pi/2))^.5
p1 = polar_plot(r(t),-pi/2,3*pi/2,fill=True,xmin=-2,xmax=2,ymin=-3,ymax=1,color='red')
r(t)=(abs(t-pi/2))^.4
p2 = polar_plot(r(t),-pi/2,3*pi/2,fill=True,xmin=-2,xmax=2,ymin=-3,ymax=1,color='red')
r(t)=(abs(t-pi/2))^.6
p3 = polar_plot(r(t),-pi/2,3*pi/2,fill=True,xmin=-2,xmax=2,ymin=-3,ymax=1,color='red')
r(t)=(abs(t-pi/2))^.2
p5 = polar_plot(r(t),-pi/2,3*pi/2,fill=True,xmin=-2,xmax=2,ymin=-3,ymax=1,color='red')
show(p1+p2+p3+p4+p5)