Java Math.expm1() method

The java.lang.Math.expm1() is used to return the Euler's number e raised to the power of a double value and subtract one form it. Here, e is an Euler's number and it is approximately equal to 2.718281828459045.

Syntax

Parameter

x = It is the exponent to raise e to in the computation of e^x -1.

Return

It returns the value of e^x - 1

If the argument is positive or negative double value, this method will return the output.
If the argument is Positive Infinity, this method will return Positive Infinity.
If the argument is Negative Infinity, this method will return -1.0.
If the argument is Zero, this method will return Zero with the same sign as the argument.
If the argument is NaN, this method will return NaN.

Example 1

public class Expm1Example1
{
    public static void main(String[] args) 
    {
        double a = 2.0;
        // return {(2.718281828459045) power of 2} - 1
        System.out.println(Math.expm1(a));
  }
}

Test it Now

Output:

6.38905609893065

Example 2

public class Expm1Example2
{
    public static void main(String[] args) 
    {
        double a = -7.0;
        // return {(2.718281828459045) power of -7} - 1
        System.out.println(Math.expm1(a));
    }
}

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Output:

-0.9990881180344455

Example 3

public class Expm1Example3
{
    public static void main(String[] args) 
    {
        double a = 0.0;
        // Input Zero, Output Zero
        System.out.println(Math.expm1(a));
    }
}

Test it Now

Output:

0.0

Example 4

public class Expm1Example4
{
    public static void main(String[] args) 
    {
        double a = 1.0 / 0;
        // Input positive Infinity, Output positive Infinity
        System.out.println(Math.expm1(a));
    }
}

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Output:

Infinity

Example 5

public class Expm1Example5
{
    public static void main(String[] args) 
    {
        double a = -1.0 / 0;
        // Input negative Infinity, Output -1
        System.out.println(Math.expm1(a));
    }
}

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Output:

-1.0

Example 6

public class Expm1Example6
{
    public static void main(String[] args) 
    {
        double a = 0.0 / 0;
        // Input NaN, Output NaN
        System.out.println(Math.expm1(a));
    }
}

Test it Now

Output: