Implement the cos x function in c language

Implement the cos x function in c language

Dazai

(Taylor McLaughlin formula)

#include <stdio.h>
#include<stdlib.h>
#include <math.h>
void main()
{
    
    
 int t,q=1;
 double x,term,factorial=1.0,sum2=1,sxm,sum1=0;
 printf("请输入cos的值：");
 scanf("%lf",&x);
      for(t=2;;t++)
      {
    
    
           factorial=factorial*t;//控制阶乘
             if(t%2==0)
      //因为是每偶次方，所以这里进行判断，可以同时控制阶乘和q的值
             {
    
    
                 sum1=sum2;
                 q=q*(-1);
                 sxm=fabs(pow(x,t));//取绝对值后的x次方    
                 term=sxm/factorial;
                 sum2=q*term+sum2;
              }
              if(fabs(sum2-sum1)<=1e-5)//定义前后两个数，控制输出精度
              break;
        }
           printf("cosx=%lf",sum2);
 }