(commands used to create figure)

>

p1:=plot({0,sqrt(2-x^2)},x=1..sqrt(2),color=aquamarine,filled=true): p2:=plot(sqrt(2-x^2),x=1..sqrt(2),color=black,thickness=2): p3:=textplot([1.3,.65,"r=sqrt(2)"],color=black,font=[TIMES,ITALIC,14],align=RIGHT): p4:=textplot([.95,0.4,"r=sec(theta)"],color=black,font=[TIMES,ITALIC,14],align=LEFT): p5:=plot(x,x=0..1.1,color=grey): p6:=textplot({[1.55,0.02,"q=0"],[1.12,1.12,"q=p/4"]},color=black,font=[SYMBOL,14],align=ABOVE): p7:=plot([1,t,t=0..1],color=red,thickness=2): display(p1,p7,p2,p3,p4,p5,p6,scaling=constrained,view=[0..1.6,0..1.2]);