code for diagram

> p1:=plot(sin(x),x=0..2*Pi,color=blue,thickness=2,
xtickmarks=[],ytickmarks=[-1.5,-1,-.5,0,.5,1,1.5],
labels=[` `,` `],axesfont=[TIMES,BOLD,12]):
txt:=plots[textplot]({[Pi/2,-.2,`Pi/2`],[Pi,-.2,`Pi`],
[(3*Pi)/2,-.2,`(3*Pi)/2`],[2*Pi,-.2,`2*Pi`]},
font=[TIMES,BOLD,12]):
plots[display]({p1,txt}, scaling=constrained ,view=[-.2..evalf(2*Pi+.4),-1.3.. 1.3]);