sin

#include <stdio.h>
#include <math.h>

double factorial(double n){
    if(n==0)
        return 1;
    return (n * factorial(n-1.0));
}

int main(){
    int i=1,flag=1;
    double sinx,term, x= (M_PI/2);
    while(i<=1000){

        term =(double) (powl(x,(double)i)/factorial((double)i));

        if(flag==1){
            sinx += term;
            flag=0;
        }else{
            sinx -= term;
            flag=1;
        }

        i += 2;
    }

    printf("sinx=>%f \nsin=>%f\n",sinx,sin(x));
    return 1;
}