# Java.lang.StrictMath.atan() Method

## Description

The java.lang.StrictMath.atan() method returns the arc tangent of a value.The returned angle is in the range -pi/2 through pi/2.It include these cases −

• If the argument is NaN, then the result is NaN.
• If the argument is zero, then the result is a zero with the same sign as the argument.

## Declaration

Following is the declaration for java.lang.StrictMath.atan() method

```public static double atan(double a)
```

## Parameters

a − This is the value whose arc tangent is to be returned.

## Return Value

This method returns the arc tangent of the argument.

NA

## Example

The following example shows the usage of java.lang.StrictMath.atan() method.

```package com.tutorialspoint;

import java.lang.*;

public class StrictMathDemo {

public static void main(String[] args) {

double d1 = 0.20 , d2 = 60.00, d3 = 0;

/* returns the arc tangent of a value, returned angle range is
-pi/2 to pi/2  */

double dAbsValue = StrictMath.atan(d1);
System.out.println("arc tangent of " + d1 + " = " + dAbsValue);

dAbsValue = StrictMath.atan(d2);
System.out.println("arc tangent of " + d2 + " = " + dAbsValue);

dAbsValue = StrictMath.atan(d3);
System.out.println("arc tangent of " + d3 + " = " + dAbsValue);
}
}
```

Let us compile and run the above program, this will produce the following result −

```arc tangent of 0.2 = 0.19739555984988078
arc tangent of 60.0 = 1.554131203080956
arc tangent of 0.0 = 0.0
```
java_lang_strictmath.htm