Java Math tanh() Method

In Java, the tanh() method is a part of the java.lang.Math class. This method returns the hyperbolic tangent of a double value passed to it as an argument.

Mathematical Definition:

The hyperbolic tangent of any value a is defined as:

((ea - e-a)/2)/((ea + e-a)/2)

where, e is Euler's number, whose value is approximately equal to 2.71828. This method returns values between -1 and 1, and that's why this function becomes very useful in various mathematical applications.

In other words, the hyperbolic tangent of a number a can also be defined as:

tanh(a) = sinh(a)/cosh(a)

Special Cases: The tanh() method handles different cases which are listed below,

• If the argument is NaN, then the result is NaN.
• If the argument is positive infinity then the result will be +1.0.
• If the argument is negative infinity then the result will be -1.0.
• If the argument is zero, then the result is zero with the same sign as that of the argument a.

Syntax of tanh() Method

public static double tanh(double a)

• Parameter: This method takes a single parameter a, which is the value whose hyperbolic tangent is to be returned.
• Return Type: This method returns the hyperbolic tangent value of the argument.

Now, we are going to discuss some examples for better understanding

Examples of Java Math tanh() Method

Example 1: In this example, we will see the basic usage of tanh() method.

// Java program to demonstrate working
// of Math.tanh() method
import java.lang.Math;

class Geeks {

    public static void main(String args[]) {
        
        double a = 3.5;
        System.out.println(Math.tanh(a)); 

        a = 90.328;
        System.out.println(Math.tanh(a)); 

        a = 0;
        System.out.println(Math.tanh(a)); 
    }
}

0.9981778976111987
1.0
0.0

Explanation: Here, we are calculating the hyperbolic tangent for given double value. For a=3.5, the result will be 0.9981778976111987 and for a=90.328, the result will be 1.0 and for a=0, the result is 0.0

Example 2: In this example, we will see how tanh() method handles NaN and Infinity.

// Java program to demonstrate working
// of Math.tanh() method in NaN and infinity case
import java.lang.Math; 

public class Geeks {
    
    public static void main(String[] args) {
        
        double p = Double.POSITIVE_INFINITY;
        double n = Double.NEGATIVE_INFINITY;
        double nan = Double.NaN;
        double res;

        // here argument is negative infinity
        res = Math.tanh(n);
        System.out.println(res);

        // here argument is positive infinity
        res = Math.tanh(p);
        System.out.println(res); 

        // here argument is NaN
        res = Math.tanh(nan);
        System.out.println(res);
    }
}

-1.0
1.0
NaN