program oken; uses crt; var i,n:integer; s:real; begin clrscr; write(‘nhap 1 so bat ky: ‘); readln(n); s:=0; for i:=2 to n do s:=s + 1/(i*i-1); writeln(‘tong S la: ‘,s:0:3); readln; end.
Dùng While-do:
program oken; uses crt; var i,n:integer; s:real; begin clrscr; write(‘nhap 1 so bat ky: ‘); readln(n); s:=0; i:=2; while i<=n do begin s:=s + 1/(i*i-1); i:=i+1; end; writeln(‘tong S la: ‘,s:0:3); readln; end.
program Cach1;
uses crt;
var i,n:integer;
S:real;
Begin
Write(‘Hay nhap so n la’); readln(n);
S:=0
for i:=1 to n do
S:=S+1/n^2-1;
Writeln(‘Tong S la:’,S);
end.
Dùng For-to-do:
program oken;
uses crt;
var i,n:integer;
s:real;
begin
clrscr;
write(‘nhap 1 so bat ky: ‘); readln(n);
s:=0;
for i:=2 to n do
s:=s + 1/(i*i-1);
writeln(‘tong S la: ‘,s:0:3);
readln;
end.
Dùng While-do:
program oken;
uses crt;
var i,n:integer;
s:real;
begin
clrscr;
write(‘nhap 1 so bat ky: ‘); readln(n);
s:=0; i:=2;
while i<=n do
begin
s:=s + 1/(i*i-1);
i:=i+1;
end;
writeln(‘tong S la: ‘,s:0:3);
readln;
end.
${Oken}$