1)var a,c:real; b:integer;beginfor b:=2 to 7 do begin c:=cos((2*b+1)/2-1); a:=0.4*c*c; writeln('b = ',b,', a = ',a:5:3); end;end.2)var a,c:real; b:integer;beginb:=1;while b<7 do begin b:=b+1; c:=cos((2*b+1)/2-1); a:=0.4*c*c; writeln('b = ',b,', a = ',a:5:3); end;end.3)var a,c:real; b:integer;beginb:=1;repeat b:=b+1; c:=cos((2*b+1)/2-1); a:=0.4*c*c; writeln('b = ',b,', a = ',a:5:3);until b=7;end.Результат:b = 2, a = 0.002b = 3, a = 0.257b = 4, a = 0.351b = 5, a = 0.018b = 6, a = 0.201b = 7, a = 0.381