36.根据公式计算值

#include<stdio.h>
double fun(double e)
{
int i, k;
double s, t, x;
s = 0;
k = 1;
i = 2;
x = 3.0 / 4;
while (x > e)
{
s = s + k*x;
k = k*(-1);
t = 2 * i;
x = (t + 1) / (t*t);
i++;
}

return s;
}

int main()
{
double e = 1e-3;
printf("The result is:%f\n",fun(e));
getchar();
return 0;
}