Program Hinh_sin;

Uses Crt, Graph; Type

Point_2D = Record

x, y : Real; End;

Const

Xmin: Real=0;

Ymin: Real=0;

Xmax: Real=639;

Ymax: Real=479;

MaxX: Integer=600;

MaxY: Integer=440;

Var

m,n : Integer;

ch: char;

CGx,CGy,x,b,Xgoc,Ygoc : Real;

p1,p2 : Point_2D;

(*********************)

Procedure WTV(p : Point_2D; Var q : Point_2D);

Begin

q.x:=p.x*CGx;

q.y:=p.y*CGy;

End;

(*********************)

Procedure VTS(p : Point_2D; Var q : Point_2D);

Begin

q.x:=Xgoc+p.x;

q.y:=Ygoc-p.y;

End;

(********************)

Procedure He_Truc;

Begin

Line(Round(Xgoc),0,Round(Xgoc),GetMaxY);

Line(0,Round(Ygoc),GetMaxX,Round(Ygoc));

End;

(*********************)

Function bp(x: Real) : Real;

Begin

bp:=Sin(x);

{ bp:=Cos(x);

bp:=Sqr(x); }

end;

(*********************)

Begin

clrscr;

m:=0;

InitGraph(m,n,'');

DirectVideo:=False;

MaxX:=GetMaxX;

MaxY:=GetMaxY;

b:=2*pi/360;

Xmin:=0;

Xmax:=2*pi;

Ymin:=-1;

Ymax:=1;

{

Xmin:=-PI+b;

Xmax:=pi-b;

Ymin:=-1;

Ymax:=1;

Xmin:=-50;

Xmax:=50;

Ymin:=0;

Ymax:=2500;

}

If Xmin>0 Then Xmin:=0;

If Ymin>0 Then Ymin:=0;

If Xmax<0 Then Xmax:=0;

If Ymax<0 Then Ymax:=0;

CGx:=MaxX/(Xmax-Xmin);

CGy:=MaxY/(Ymax-Ymin);

Xmin:=CGx*Xmin;

Xmax:=CGx*Xmax;

Ymin:=CGy*Ymin;

Ymax:=CGy*Ymax;

Xgoc:=0;

If Xgoc>Xmin Then Xgoc:=Round(ABS(Xmin)); Ygoc:=0;

If Ygoc<Ymax Then Ygoc:=Round(ABS(Ymax)); He_Truc;

x:=Xmin;

p1.x:=x; p1.y:=bp(x); WTV(p1, p2);

p1:=p2; VTS(p2, p2);

MoveTo(Round(p2.x),Round(p2.y)); Repeat

p1.x:=x; p1.y:=bp(x);

WTV(p1, p2);

p1:=p2; VTS(p2, p2);

LineTo(Round(p2.x),Round(p2.y));

x:=x+b;

Until x>2*pi-Xmin+b; Readln;

CloseGraph;

End.