#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <locale.h>
int main(void)
{
setlocale(LC_ALL, "Russian");
const double eps=0.00001;
double F, x, s, s1=0.0;
int k=1;
printf ("Введите X:\n");
scanf ("%lf", &x);
s=x;
F=0;
do
{
s1=s1+F;
F=cos(k*x)/k*k;
s=s+F;
k++;
}
while (abs(s1-s)>eps);
printf ("%lf", s);
system("PAUSE");
return 0;
}