Операторы IF . THEN, CASE

unit Unit1;
 
interface
 
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls,Math;//добавить
 
type
  TForm1 = class(TForm)
    Button1: TButton;
    Edit1: TEdit;
    Edit2: TEdit;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
 
var
  Form1: TForm1;
 
implementation
 
{$R *.dfm}
 
procedure TForm1.Button1Click(Sender: TObject);
var x,a,b,y,z:real;
begin
x:=StrToFloat(Edit1.Text);
a:=4.51;
b:=9.89;
if x>b then
 begin
  y:=a*exp(2*b)-sin(sqr(arctan(x)*arctan(x)));
  Edit2.Text:='y='+FloatToStr(RoundTo(y,-3))
 end
else
 begin
  z:=sin(sqr(cos(x)))+sqrt(x+exp(a+b*x));
  Edit2.Text:='z='+FloatToStr(RoundTo(z,-3))
 end
end;
 
end.

program Project2;
 
{$APPTYPE CONSOLE}
 
uses
  SysUtils;
var x,a,b,y,z:real;
begin
write('x=');
readln(x);
a:=4.51;
b:=9.89;
if x>b then
 begin
  y:=a*exp(2*b)-sin(sqr(arctan(x)*arctan(x)));
  write('y=',y:0:3)
 end
else
 begin
  z:=sin(sqr(cos(x)))+sqrt(x+exp(a+b*x));
  write('z=',z:0:3)
 end;
readln
end.

program Project2;
 
{$APPTYPE CONSOLE}
 
uses  SysUtils,Math;
var x,a,b,y,z,v:real;
    k:char;
begin
write('x=');
readln(x);
a:=4.51;
b:=9.89;
write('Kluch=[a,b,c] k=');
readln(k);
case k of
'a':begin
     y:=a*exp(2*b)-sin(sqr(arctan(x)*arctan(x)));
     write('kluch=',k,'  y=',y:0:3)
    end;
'b':begin
     z:=sin(sqr(cos(x)))+sqrt(x+exp(a+b*x));
     write('kluch=',k,'  z=',z:0:3)
    end;
'c':begin
     v:=(tan(x)-b)/(a*(b+power(x,b)));
     write('kluch=',k,'  v=',v:0:3)
    end;
else write('Neverno veden kluch');
end;
 
readln
end.