The "atan" function is used for calcution of the arc tangent value of a given input.
double atan(double x);
The "atan" function accepts 1 parameters
#include <stdio.h> #include <math.h> #include<conio.h> int main() { double x,atan_value; clrscr(); printf("\nEnter the number : "); scanf("%lf",&x); atan_value = atan(x); printf("The arc tangent value is %lf\n", atan_value); getch(); return 0; }