uses crt;
const k=15;
function Ch(x:real;n:integer):real;
begin
if n=0 then Ch:=1
else Ch:=Ch(x,n-1)*x*x/(2*n*(2*n-1));
end;
var x,s:double;
i:integer;
begin
clrscr;
x:=0.7;
s:=0;
for i:=0 to k do
s:=s+Ch(x,i);
writeln('Ch(x)=',s:0:5);
writeln('аналитически=',(exp(x)+exp(-x))/2:0:5);
readln
end.