sin(x+y)=sinxcosy+cosx+siny;
cos(x+y)=cosxcosy-sinxsiny
tan(x+y)=(tanx+tany)/(1-tanx * tany);
sin2x=2sinxcosx;
cos2x=(cosx)^2-(sinx)2
sin(x+y)=sinxcosy+cosx+siny;
cos(x+y)=cosxcosy-sinxsiny
tan(x+y)=(tanx+tany)/(1-tanx * tany);
sin2x=2sinxcosx;
cos2x=(cosx)^2-(sinx)2