Ábrázoljuk a grafikus képernyőn a következő függvényeket:

y=0.5x+2; (egyenes)

y=x⁴-6x²+3; (negyedfokú függvény)

(x+6)²+(y-3)²=4; (kör)

y=sin(x). (Sinus görbe)

A futási kép:

A program listája:

Program Grafikon;

Uses NewDelay, Crt, Graph;

Const D=50;

Dx=0.1;

Var Xm,Ym, Xk,Yk, I,J: Integer;

Sz: String;

A,B,C, X,Y: Real;

Procedure GrInit;

Var Gd,Gm: Integer;

Begin

Gd:= InstallUserDriver('svga256',Nil); Gm:=4;

InitGraph(Gd,Gm,'C:\Tp\Bgi');

If GraphResult<>0 Then Halt;

Xm:= GetMaxX; Ym:= GetMaxY;

Xk:= Xm Div 2; Yk:= Ym Div 2;

End;

Function PontX(R: Real): Integer;

Begin

PontX:= Round(Xk+R*D);

End;

Function PontY(R: Real): Integer;

Begin

PontY:= Round(Yk-R*D);

End;

Begin

GrInit;

SetFillStyle(1,15); Bar(0,0, Xm,Ym);

SetColor(0);

Line(0,Yk, Xm,Yk); Line(Xk,0, Xk,Ym);

MoveTo(Xm-5,Yk-5); LineTo(Xm,Yk); LineTo(Xm-5,Yk+5);

MoveTo(Xk-5,5); LineTo(Xk,0); LineTo(Xk+5,5);

Circle(Xk,Yk,4);

For I:= -10 To 10 Do

Begin

Line(Xk+I*D,Yk-4,Xk+I*D,Yk+4); Str(I,Sz);

If I<0 Then OutTextXY(Xk+I*D-7,Yk+6,Sz);

If I>0 Then OutTextXY(Xk+I*D-3,Yk+6,Sz)

End;

For I:= -7 To 7 Do

Begin

Line(Xk-4,Yk-I*D,Xk+4,Yk-I*D); Str(I,Sz);

If I<0 Then OutTextXY(Xk-22,Yk-I*D-4,Sz);

If I>0 Then OutTextXY(Xk-14,Yk-I*D-4,Sz);

End;

For I:= -10 To 10 Do

For J:= -7 To 7 Do PutPixel(Xk+I*D,Yk-J*D,0);

SetColor(Red);

A:= 0.5; B:= 2; {y=0.5x+2}

X:= -10; MoveTo(PontX(X),PontY(A*X+B));

Repeat

X:= X+Dx; Y:= A*X+B; LineTo(PontX(X),PontY(Y));

Until X>10;

SetColor(Blue); {(x+6)²+(y-3)²=4}

Circle(PontX(-6),PontY(3),2*D);

SetColor(Black);

A:= 1; B:= -6; C:= 3; {y=x⁴-6x²+3}

X:= -6; MoveTo(PontX(X),PontY(A*X*X*X*X+B*X*X+C));

Repeat

X:= X+Dx; Y:= A*X*X*X*X+B*X*X+C;

LineTo(PontX(X),PontY(Y));

Until X>6;

{y=sin(x)}

SetColor(Green);

X:= -10; MoveTo(PontX(X),PontY(Sin(X)));

Repeat

X:= X+Dx; Y:= Sin(X); LineTo(PontX(X),PontY(Y));

Until X>10;

ReadKey;

CloseGraph;

End.