import graph_pi;

graphicrules(xunit=1cm, yunit=2cm,
             xmin=-2pi, xmax=2pi, ymin=-1, ymax=1);

yaxis("y",LeftRight ,
      Ticks(labelfrac,Step=.5,step=.25, ptick=grey, extend=true));

xaxis("$\theta$",BottomTop,
      Ticks(labelfrac(factor=pi,symbol="\pi",symbolin=false),
            Step=pi/2, step=pi/4, ptick=grey, extend=true));

draw(graph(new real(real x){return sin(x);},-2pi,2pi));
draw(graph(new real(real x){return cos(x);},-2pi,2pi), .8red);