> #lecture9
> with(plots):
> polarplot(sin(theta),theta=0..2*Pi,scaling=constrained);
> polarplot(cos(theta),theta=0..2*Pi,scaling=constrained);
> expand(r*(r-sin(theta)));
> x^2+y^2-y;
> polarplot(sin(2*theta),theta=0..2*Pi,scaling=constrained);
> polarplot(sin(3*theta),theta=0..2*Pi,scaling=constrained);
> polarplot(sin(4*theta),theta=0..2*Pi,scaling=constrained);
> 
> polarplot(sin(5*theta),theta=0..2*Pi,scaling=constrained);
> polarplot(1+cos(theta),theta=0..2*Pi,scaling=constrained);
> polarplot(1,theta=0..2*Pi,scaling=constrained);
> polarplot(theta/10,theta=0..2*Pi,scaling=constrained);
> polarplot(2/cos(theta),theta=-Pi/4..Pi/4,scaling=constrained);
> polarplot(sin(theta)/(cos(theta))^2,theta=-Pi/4..Pi/4,scaling=constrained);
> a:=plot3d({1,0},x=0..1,y=0..x,color=red):a;
> b:=plot3d({1,0},y=0..x,x=0..1,color=green,title=`wrong way`):b;
> display(a,b,scaling=constrained);
> plot3d({6-x-2*y,0},x=0..6,y=0..3-x/2);
>