code for diagram

> p1:=plot(arcsin(x),x=-1..1,thickness=3):

> disks:=plot({seq([i/2,arcsin(i/2)] ,i=-2..2)},style=POINT,symbol=CIRCLE,color=black):

> txt:=[-.2,-Pi/2.,`-Pi/2`],[-.2,-Pi/6.,`-Pi/6`],
[-.2, Pi/2.,` Pi/2`],[-.2, Pi/6,`Pi/6`]:
TXT:=plots[textplot]({txt},font=[TIMES,BOLD,12]):

> plots[display]({p1,TXT,disks},xtickmarks=[-1,-.5,.5,1],
ytickmarks=[],axesfont=[TIMES,BOLD,12],
view=[-1.5..1.5,(-Pi/2-.5)..(
Pi/2+.5)],scaling=constrained,labels=[` `,` `]);