28.4527 setxunit %% 10 mm
%40 setxunit
-2 9 setxrange
-1.5 1.5 setyrange

%[1 1 .5 .5 .1 .1] {orange} Quadrillage

traceaxes marks axesarrow

/f {setxvar x Sin} def

1.5 setlinewidth
{f} courbe 

/x1 0.6 def
/M1 {x1 x1 f} def
/x2 {pi x1 sub} def
/M2 {x2 x2 f} def

0.7 setlinewidth
M1 dashpoint
M2 dashpoint

mixte
1.54 -1 1.54 1 droite