diffsin_richardson.c

#include<stdio.h>
#include<math.h>
double f(double x,double h){
    return (sin(x+h)-sin(x))/h;
}
int main(){
    double h = 1 / pow(2,16);
    double a1 = (4*f(1,h) - f(1,2*h))/3;
    printf("cos(1) = %.12f \nd/dx sin(1) = %.12f",cos(1),a1);
    return 0;
}