#3) Graph Roses with Horizontal Symmetry
show(polar_plot([cos(2*theta)],(theta,0,2*pi),aspect_ratio=1))
show(polar_plot([cos(3*theta)],(theta,0,2*pi),aspect_ratio=1))
show(polar_plot([cos(4*theta)],(theta,0,2*pi),aspect_ratio=1))
show(polar_plot([cos(5*theta)],(theta,0,2*pi),aspect_ratio=1))
show(polar_plot([cos(6*theta)],(theta,0,2*pi),aspect_ratio=1))
show(polar_plot([cos(7*theta)],(theta,0,2*pi),aspect_ratio=1))