Calculating sine of radian in C

Question

Working on a simple school problem using C to calculate sine of 1 radian.

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

int main(int argc, const char * argv[])
{

     double radian = (180 / M_PI);
     double y = sin(radian);
     printf("The sine of 1 radian is %.3f", y);

     return 0;
}

The sine of a radian is 0.841, but I'm getting 0.680. Is this because of how I am calculating 1 radian, instead of just using radians?

Answer 1

180 / pi is one radian IN DEGREES.
But the sin() function takes a value in radian.
So it's just sin(1).