1import math; 2import graph; 3 4size(0,150); 5 6real f(real t) {return 5+cos(10*t);} 7 8xaxis("$x$"); 9yaxis("$y$"); 10 11real theta1=pi/8; 12real theta2=pi/3; 13path k=graph(f,theta1,theta2,operator ..); 14real rmin=min(k).y; 15real rmax=max(k).y; 16draw((0,0)--rmax*expi(theta1),dotted); 17draw((0,0)--rmax*expi(theta2),dotted); 18 19path g=polargraph(f,theta1,theta2,operator ..); 20path h=(0,0)--g--cycle; 21fill(h,lightgray); 22draw(h); 23 24real thetamin=3*pi/10; 25real thetamax=2*pi/10; 26pair zmin=polar(f(thetamin),thetamin); 27pair zmax=polar(f(thetamax),thetamax); 28draw((0,0)--zmin,dotted+red); 29draw((0,0)--zmax,dotted+blue); 30 31draw("$\theta_*$",arc((0,0),0.5*rmin,0,degrees(thetamin)),red+fontsize(10pt), 32 PenMargins); 33draw("$\theta^*$",arc((0,0),0.5*rmax,0,degrees(thetamax)),blue+fontsize(10pt), 34 PenMargins); 35 36draw(arc((0,0),rmin,degrees(theta1),degrees(theta2)),red,PenMargins); 37draw(arc((0,0),rmax,degrees(theta1),degrees(theta2)),blue,PenMargins); 38 39