Построение Графиков Функции

program Grafik;
uses Crt,
Graph;
const
grPath = 'f:\tp7\bgi';
A = 50;
B = 70;
 
var
grDriver, grMode: Integer;
MidX, MidY: Integer;
g: Integer;
t: Real;
X, Y: Real;
 
begin
grDriver := Detect;
InitGraph(grDriver, grMode, grPath);
MidX := GetMaxX div 2;
MidY := GetMaxY div 2;
 
Setbkcolor(Red);
setlinestyle(solidln,2,NormWidth);
 
Line(10,midY, GetMaxX-2,midY);
Line(midX, 2,midX, GetMaxY-2);
moveto(midx,2);linerel(-2,5);
moveto(midx,2);linerel(2,5);
 
moveto(GetMaxX-2,midy);linerel(-5,-2);
moveto(GetMaxX-2,midy);linerel(-5,2);
 
 
for g := 0 to 360 do begin
t := g * Pi / 180;
X := MidX + A * Sqr(Cos(t)) + B * Cos(t);
Y := MidY + A * Cos(t) * Sin(t) + B * Sin(t);
if g = 0 then
MoveTo(Round(X), Round(Y))
else
LineTo(Round(X), Round(Y));
end;
outtextxy(370,470,'D/\9l BblXoDa Ha}l{MuTe Enter :)');
ReadKey;
CloseGraph;
end.

program EvgeniiSp;
uses GraphABC, Events;
 
//------- Solution_y ------//
 function Solution_y(a,b,t: real): real;
  begin
   result:=a*cos(t)*sin(t)+b*sin(t);  // åñëè õn - îòðàöèòåëåí, òî áðàòü abs(x);
  end;
 
//------- Solution_x ------//
 function Solution_x(a,b,t: real): real;
  begin
   result:=a*sqr(cos(t))+b*cos(t);  // åñëè õn - îòðàöèòåëåí, òî áðàòü abs(x);
  end;
  
//-------- Drawing_graph ------//
 procedure Drawing_graph(color: integer);
  const
   a = 2;
   b = 3;
   dt = 0.1; tn = 0; tk = 2*pi;
  var
   ww,wh,xs,ys: integer;
   x,y,ymax,xmax,t: real;
 
 //------- Conversion_y ------//
  function LogicToScreen_y(y: real): real;
   begin
    result:=(wh div 2)*y/ymax;
   end;
 
 //------- Conversion_x ------//
  function LogicToScreen_x(x: real): real;
   begin
    result:=(ww div 2)*x/xmax;
   end;
 
  begin
   y:=0;
   SetPenWidth(1);
   ww:=WindowWidth-50;
   wh:=WindowHeight-50;
   SetPenColor(clGray);
   TextOut((ww div 2)-10,(wh div 2)+4,'0');
   moveTo(0,wh div 2);
   lineTo(ww+50,wh div 2);
   TextOut(ww-12+50,(wh div 2)+3,'X');
   moveTo(ww div 2,0);
   lineTo(ww div 2,wh+50);
   TextOut((ww div 2)+5,3,'Y');
//-------------------------
   t:=tn;
   ymax:=0;
   xmax:=0;
   while t <= tk do
    begin
     y:=Solution_y(a,b,t);
     x:=Solution_x(a,b,t);
     if abs(y) > ymax then ymax:=abs(y);
     if abs(x) > xmax then xmax:=abs(x);
     t:=t+dt;
    end;
//-------------------------
   t:=tn;
   SetPenWidth(1);
   SetPenColor(color);
   while t <= tk do
    begin
     y:=Solution_y(a,b,t);
     x:=Solution_x(a,b,t);
     ys:=Round(LogicToScreen_y(y));
     xs:=Round(LogicToScreen_x(x));
     if t = tn then moveTo((ww div 2)+xs,(wh div 2)-ys)
        else lineTo((ww div 2)+xs,(wh div 2)-ys);
     t:=t+dt;
    end;
   Redraw;
  end;
 
//-------- Resize ------//
 procedure Resize;
  begin
   ClearWindow;
   Drawing_graph(clRed);
   Redraw;
  end;
 
begin
 SetWindowCaption('Ãðàôèê ôóíêöèè.');
 SetWindowSize(700,500);
 LockDrawing;
 CenterWindow;
 Drawing_graph(clRed);
 OnResize:=Resize;
end.