code for graph

> pt:=plot(3*sin(2*Pi*x/2),x=-1..5,thickness=3,
xtickmarks=[],ytickmarks=[]):
dotline:=plot({[[0,3],[2,3]],[[0,-3],[2,-3]]},thickness=1,linestyle=3):
Btext:=plots[textplot]({[-.2,-.2,`0`],[1.8,-.2,`B`],[3.8,-.2,`2B`]},align=BELOW,font=[TIMES,BOLD,16]):
Atext:=plots[textplot]({[ -.2,3,`A`],[ -.2,-3,`-A`]},align=BELOW,font=[TIMES,BOLD,16]):

> plots[display]([dotline,pt,Btext,Atext],view=[-1..5,-4..4]);