Atan Function

Syntax:

float atanf(float arg);

double atan(double arg);

long double atanl(long double arg);

Example:

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

  int main()
  {
    double x = -1.0;
	
    do {
      printf("Arc tangent of %f is %f.\n", x, atan(x));
      x += 0.1;
    } while(x<=1.0);

    return 0;
  }