Java Math tanh()

The hyperbolic tangent is equivalent to (e^x - e^-x)/(e^x + e^-x), where e is Euler's number. Also tanh = sinh/cosh.

The syntax of the tanh() method is:

 Math.tanh(double value)

Here, tanh() is a static method. Hence, we are accessing the method using the class name, Math.

tanh() Parameters

The tanh() method takes a single parameter.

• value - angle whose hyperbolic tangent is to be determined

Note: The value is generally used in radians.

tanh() Return Values

• returns the hyperbolic tangent of value
• returns NaN if the argument value is NaN
• returns 1.0 if the argument is positive infinity
• returns -1.0 if the argument is negative infinity

Note: If the argument is zero, then the method returns zero with the same sign as the argument.

Example 1: Java Math tanh()

 class Main { public static void main(String[] args) { // create a double variable double value1 = 45.0; double value2 = 60.0; double value3 = 30.0; // convert into radians value1 = Math.toRadians(value1); value2 = Math.toRadians(value2); value3 = Math.toRadians(value3); // compute the hyperbolic tangent System.out.println(Math.tanh(value1)); // 0.6557942026326724 System.out.println(Math.tanh(value2)); // 0.7807144353592677 System.out.println(Math.tanh(value3)); // 0.4804727781564516 } }

In the above example, notice the expression,

 Math.tanh(value1)

Here, we have directly used the class name to call the method. It is because tanh() is a static method.

Note: We have used the Java Math.toRadians() method to convert all the values into radians.

Example 2: Compute tanh() Using sinh() and cosh()

 class Main { public static void main(String[] args) { // create a double variable double value1 = 45.0; double value2 = 60.0; double value3 = 30.0; // convert into radians value1 = Math.toRadians(value1); value2 = Math.toRadians(value2); value3 = Math.toRadians(value3); // compute the hyperbolic tangent: sinh()/cosh() // returns 0.6557942026326724 System.out.println(Math.sinh(value1)/Math.cosh(value1)); // returns 0.7807144353592677 System.out.println(Math.sinh(value2)/Math.cosh(value2)); // returns 0.4804727781564516 System.out.println(Math.sinh(value3)/Math.cosh(value3)); } }

In the above example, notice the expression,

 Math.sinh(value1)/Math.cosh(value2)

Here, we are computing the hyperbolic tangent using sinh()/cosh() formula. As we can see the result of tanh() and sinh()/cosh() is same.

Example 2: tanh() With Zero, NaN and Infinite

 class Main { public static void main(String[] args) { // create a double variable double value1 = Double.POSITIVE_INFINITY; double value2 = Double.NEGATIVE_INFINITY; double value3 = Math.sqrt(-5); double value4 = 0.0; // convert into radians value1 = Math.toRadians(value1); value2 = Math.toRadians(value2); value3 = Math.toRadians(value3); value4 = Math.toRadians(value4); // compute the hyperbolic tangent System.out.println(Math.tanh(value1)); // 1.0 System.out.println(Math.tanh(value2)); // -1.0 System.out.println(Math.tanh(value3)); // NaN System.out.println(Math.tanh(value4)); // 0.0 } }

In the above example,

• Double.POSITIVE_INFINITY - implements positive infinity in Java
• Double.NEGATIVE_INFINITY - implements negative infinity in Java
• Math.sqrt(-5) - square root of a negative number is not a number

We have used the Java Math.sqrt() method to calculate the square root of a number.

Note: The tanh() method returns 1.0 for the positive infinity argument and -1.0 for the negative infinity argument.

Also Read:

• Java Math.sinh()
• Java Math.cosh()