uses crt;
const e=0.0001;
var xn,xk,x,s,si,dx,t,at:real;
    n:integer;
begin
clrscr;
repeat
write('vvedite nachalo intervala xn<-1 xn=');
readln(xn);
until xn<-1;
repeat
write('vvedite konec intervala, bolshe ',xn:0:1,' <-1 xk=');
readln(xk);
until (xk>xn)and(xk<-1);
repeat
write('vvedite shag tabulyacii, menshe ',xk-xn:0:1,' dx=');
readln(dx);
until dx<xk-xn;
clrscr;
x:=xn;
writeln('       Tabulirpovanie funkcii F(x)=arctg(x),');
writeln('     predstavlennoy razlosheniem v stepennoy ryad');
writeln('        na intervale ',xn:0:1,'..',xk:0:1,' s shagom ',dx:0:1);
writeln;
writeln('        -----------------------------------');
writeln('        |   X   |    S    |  arctg  |  n  | ');
writeln('        -----------------------------------');
while x<=xk+dx/2 do
 begin
  s:=0;
  si:=-1/x;
  t:=-1/x;
  n:=0;
  while abs(s-si)>=e do
   begin
    n:=n+1;
    s:=si;
    t:=-t/(x*x);
    s:=s+t/(2*n+1);
   end;
  s:=-pi/2+s;
  at:=arctan(x);
  writeln('        |',x:6:1,' |',s:8:2,' |',at:8:2,' | ',n:4,'|');
  x:=x+dx;
 end;
writeln('        -----------------------------------');
readln
end.