Program Pascal Persamaan Non Linier Biseksi dan Regular Falsi

program Persamaan_non_linier;
uses wincrt;
var
x,x1,x2,xa,xb,xc,y,y1,y2,ya,yb:real;
I,j,k:integer;
replay:char;
pilihan:integer;
x3,y3:real;
begin
    repeat
      writeln('PILIHAN PROGRAM');
      writeln;
      writeln('1.program metode biseksi');
      writeln('2.program regula falsi');
      writeln;
      writeln('pilihan anda? ');
      readln(pilihan);
    if (pilihan=1) then
 begin
     writeln('tentukan nilai akar persamaan f(x)=x^3+x^2-3x=0 dgn metode biseksi');
     write('masukan nilai x1= ');
     readln(x1);
     y1:=x1*x1*x1+x1*x1-3*x1-3;
     writeln('  nilai f(x1)=',y1:0:4);
     repeat
     begin
     write('masukan nilai x2= ');
     readln(x2);
     y2:=x2*x2*x2+x2*x2-3*x2-3;
     write('  nilaif(x2)=',y2:0:4);
     end;
     if (y1*y2)<0 then
     writeln(' nilai ok')
     else
     writeln(' nilai x2 belum sesuai');
     until (y1*y2)<0;
     i:=2;
     writeln;

     writeln('penyelesaian persamaan dgn metode biseksi,nilai x1=',x1:0:2,' & x2=',x2:0:2);
     writeln('----------------------------------------------------');
     writeln(' n         x           f(x)          error       ');
     writeln('----------------------------------------------------');
     repeat
       begin
         i:=i+1;x3:=(x1+x2)/2;
         y3:=x3*x3*x3+x3*x3-3*x3-3;
         if (i mod 10)=0 then readln;
         if 1<10 then
            writeln('',i,'::',x3,'::',y3,'::',abs(y3),'::')
             else writeln(i,'::',x3,'::',y3,'::',abs(y3),'::');
             if (y1*y3)<0 then
                begin
                x2 :=x3;
                end else
                  begin
                  x1:=x3;
                  end;
                  end;
                  until abs(y3)<1e-07;
                  writeln('--------------------------------------');
                  writeln('akar persamaan nya=',x3);
                  writeln('errornya=',abs(y3));
                  writeln('--------------------------------------');
                   write('apakah anda ingin mengulangi?y/n: ');
                readln(replay);



 end;

           if(pilihan=2) then
           begin
              writeln('tentukan nilai akar dari persamaan f(x)x^3+x^2-3x-3 dengan regula falsi');
              write('masukan nilai x1= ');readln(x1);
              y1:=x1*x1*x1+x1*x1-3*x1-3;
              writeln(' nilai f(x1)=',y1:0:4);
              repeat
                begin
                write('masukan nilai x2= ');readln(x2);
                y2:=x2*x2*x2+x2*x2-3*x2-3;
                write(' nilai f(x2)=',y2:0:4);
                end;
                if (y1*y2)<0 then
                writeln(' nilai ok')
                else
                writeln(' nilai x2 belum sesuai');
                until (y1*y2)<0;
                writeln;
                writeln('penyelesaian persamaan karakteristik dengan metode regula falsi');
                writeln('------------------------------------------------------');
                writeln(' n          x           f(x)           error       ');
                writeln('------------------------------------------------------');
                repeat
                  begin
                   i:=i+1;x3:=(x2-(y2/(y2-y1))*(x2-x1));
                   y3:=x3*x3*x3+x3*x3-3*x3-3;
                   if i<10 then
                    writeln('',i,':',x3,':',y3,':',abs(y3),': ')
                    else
                      writeln(i,':',x3,':',y3,':',abs(y3),':');
                      if (y1*y3)<0 then
                        begin
                          x2:=x3;y2:=y3;
                          end
                            else
                              begin
                                x1:=x3;y1:=y3;
                                end;
                                 end;
                                 until abs(y3)<1e-08;
                 writeln('-----------------------------------------------------');
                 writeln('akar persamaan nya=',x3);
                 writeln('errornya=',abs(y3));
                 writeln('-----------------------------------------------------');
                write('apakah anda ingin mengulangi?y/n: ');
                readln(replay);
           end;


until replay ='n';
end.