Function GOLDEN(AX, BX, CX, TOL:real;var XMIN:real):real;
const
    R = 0.61803399;  C = 0.38196601;
Var
    X0,X3,X1,X2,F0,F1,F2,F3:real;
begin
    X0:=AX;
    X3:=CX;
    If Abs(CX - BX) > Abs(BX - AX) Then
    Begin
        X1:=BX;
        X2:=BX + C * (CX - BX);
    end
    Else
    begin
        X2:=BX;
        X1:=BX - C * (BX - AX);
    end;
    F1:=FUNC(X1);
    F2:=FUNC(X2);
    While Abs(X3 - X0) > TOL * (Abs(X1) + Abs(X2)) do
    begin
        If F2 < F1 Then
        begin
            X0:=X1;
            X1:=X2;
            X2:=R * X1 + C * X3;
            F0:=F1;
            F1:=F2;
            F2:=FUNC(X2);
        end
        Else
        begin
            X3:=X2;
            X2:=X1;
            X1:=R * X2 + C * X0;
            F3:=F2;
            F2:=F1;
            F1:=FUNC(X1);
        end;
    end;
    If F1 < F2 Then
    begin
        GOLDEN:=F1;
        XMIN:=X1;
    end
    Else
    begin
        GOLDEN:=F2;
        XMIN:=X2;
    end;
end;