C语言计算sinx （不是很懂题目的意思

Question

Answer 1

#include<conio.h>
#include <math.h>
#include<stdio.h>
int main()
{
    double x=0.8;
    double sinx=x;
    double k=-1;
    double n=1;
    double i=1;
    double xx=x;
    double y;
    do{
        xx *= x*x;
        n *=(i+1)*(i+2);
        y= xx /n;
        sinx += k*y;
        k = -k;
        i+=2;
    }while( y > 10e-7);
    printf("sinx =%f\n",sinx);
    return 0;
}