使用无限级数展开计算角度x的正弦值

这里给出了无限级数展开的公式：

sin x = x - x3/3! + x5/5! - x7/7! + ...

这里，x是弧度，它取值范围-1 <= x <= 1。

#include <stdio.h>

int main()
{
     double sine, term, x = 0.7, z;
     int k  = 1;
     char ch;

     term = x;
     sine = x;
     z = x * x;

     for (int i = 1; i <= 10; i++) {
       k = k + 2;
       term = -term * z /(k * (k - 1));
       sine = sine + term;
     }

     printf("Sine of %lf is %lf\n", x, sine);
     return(0);
}