{{keywords>wiki library source code example reference}}
===== sin =====
<code cpp>
     double sin(double);
</code>
return the sinus

===== cpp Sourcecode Example =====
<code cpp>     
#include <iostream> /* including standard library */
#include <cmath> /* including math library */

using namespace std;
int main (void)
{
  double x;
  x = 42.0;

  //cout.setf(ios::fixed, ios::floatfield);
  cout.precision(8);

  cout << "sine of " << x << "° is " << sin(x*3.1415/80) << endl;;
  return 0;
}
</code>

==== output ====
    sine of 42° is 0.99692115