#include <stdio.h>
#include <math.h>

double funcos( double e, double x );

int main()
{   
    double e, x;

    scanf("%lf %lf", &e, &x);
    printf("cos(%.2f) = %.6f\n", x, funcos(e, x));

    return 0;
}
double funcos( double e, double x )

{
    int n=0,flag=-1;
    long p=1;
    double power,item,sum;
    sum=0;
    while (fabs(item)>=e)
    {
        power = pow(x,n);
        p = fact(n);
        item = flag*power/p;
        sum = sum+item;
        n =n+2;
        flag = -flag;
    }
    return sum;
}
long fact (n)
{   
    int i;
    long result =1;
    for (i=2;i<=n;i++)
    {
        result*=i;
    }
    return result;
}

#include <stdio.h>
#include <math.h>

double funcos(double e, double x);
long fact(int n);                 //函数声明
int main()
{
    double e, x;

    scanf("%lf %lf", &e, &x);
    printf("cos(%.2f) = %.6f\n", x, funcos(e, x));

    return 0;
}
double funcos(double e, double x)

{
    int n = 0, flag = 1;   //第一项是正数，所以flag=1
    long p = 1;
    double power, item, sum;
    item = 999999;      //给item赋个初始值让while循环跑起来
    sum = 0;
    while (fabs(item) >= e)
    {
        power = pow(x, n);
        p = fact(n);
        item = flag*power / p;
        sum = sum + item;
        n = n + 2;
        flag = -flag;
    }
    return sum;
}
long fact(int n)      //函数声明n的类型呢?
{
    int i;
    long result = 1;
    for (i = 2; i <= n; i++)
    {
        result *= i;
    }
    return result;
}