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Atan / Atanl Function >> Math.h >> Header File in C

Atan / Atanl :

  1. The atan() function returns the arc Tangent of an argument
  2. Atan return the arc tangent of the input value [ in the range -PI/2 to PI/2 ]
  3. Header File : Math.h

Syntax :

double atan( double arg );
long double atanl(long double (x));


Live Example :


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

#define PI 3.14159265

int main ()
{
  double para, result;
  param = 1.0;
  result = atan (para) * 180 / PI;
  printf ("The arc tangent of %lf is %lf degreesn", para,result );
  return 0;
}


Output :


The arc tangent of 1.000000 is 45.000000 degrees.