The java.lang.Math.atan() returns the arc tangent of an angle in between -pi/2 through pi/2. If the argument is NaN, then the result is NaN.
Note:If the argument is zero, then the result is a zero with the same sign as the argument.
Syntax :
public static double atan(double a) Parameter : a : the value whose arc tangent is to be returned. Return : This method returns the arc tangent of the argument.
Example :To show working of java.lang.Math.atan() method.
// Java program to demonstrate working// of java.lang.Math.atan() methodimport java.lang.Math;  class Gfg {      // driver code    public static void main(String args[])    {        double a = Math.PI;          System.out.println(Math.atan(a));          double c = 344.0;        double d = 0.0;        double e = -0.0;        double f = 1.5;          System.out.println(Math.atan(c));          // Input positive zero        // Output positive zero        System.out.println(Math.atan(d));          // Input negative zero        // Output negative zero        System.out.println(Math.atan(e));          System.out.println(Math.atan(f));    }} |
Output:
1.2626272556789115 1.5678893582391513 0.0 -0.0 0.982793723247329
