C语言中怎么求sinx的近似值

Question

#include
#include
void main()
{
int i,n,b=1,c=0,m;
float x;
double a,d,e=0;
scanf("%f%d",&x,&n);
for(i=1;i<=(4*n+1);i+=2)
{
c+=1;
a=pow(x,i);
for(m=1;m<=i;m++)
{
b*=m;
}
d=a/b*pow(-1,(c+1));
e+=d;
}
printf("%.50f\n",e);
}

Answer 1

d=a/b
->
d=a/(double)b