program JIP7;
uses Crt, Graph;
const
   A = 15;
   F = 500;
   T = 1/F;
   M = 8;
   Xmax = M*T;
   Ymax = 2;
   cx = 10;
   cy = 240;
   sx = (640-cx) / Xmax;
   sy = (480-cy) / Ymax;
function CoordX(X: integer): Integer;
var
   RezX:LongInt;
begin
   RezX:=Trunc(X*sx)+cx;
   if RezX > $FFFF then
     RezX := Integer(RezX);
   if RezX < cx then
     RezX := cx
   else if RezX > 640 then
     RezX := 640;
   CoordX := RezX
end;
function CoordY(Y: integer): Integer;
var
   RezY: LongInt;
begin
   RezY := cy - Trunc(Y * sy);
   if RezY > $FFFF then
     RezY := Integer(RezY);
   if RezY < 0 then
     RezY := 0
   else if RezY > 480 then
     RezY := 480;
   CoordY := RezY
end;
var
   gd,gm:integer;
   X,Y, step: integer;
begin
   gd:=detect;
   gm:=2 ;
   Initgraph(gd,gm,'');
   SetColor(13);
   MoveTo(cx, cy);
   step:=round(Xmax/(640-cx));
   X := step;
   while X <= Xmax do
   begin
     Y := round(A*Sin(2*Pi*F*X));
     LineTo(CoordX(X), CoordY(Y));
     X := X + step
   end;
   SetColor(15);
   Line(cx,cy,       640,cy);
   Line(cx,0,        cx,480);
   repeat until KeyPressed;
   Closegraph
end.