# StrictMath expm1() Method in Java With Examples

• Last Updated : 13 Dec, 2021

The java.lang.StrictMath.expm1() is an inbuilt method in Java which is used to return the exponential e^num -1 for a given value of num. The method gives rise to four different cases:

• The method returns NaN when the given argument is NaN.
• The result is positive infinity when the argument is positive infinity.
• The result is negative infinity when the argument is negative infinity.
• For 0 the methods return 0 with the same sign as the argument.

Syntax :

`public static double expm1(double num)`

Parameters: This method accepts one parameter num of double type and refers to the value on which the exponential operation is to be performed.
Return Value: The method will return the result of enum – 1 operation.
Examples :

```Input: num = (1.0/0.0)
Output: Infinity

Input: 32.2
Output: 9.644557735961714E13```

Below programs illustrate the java.lang.StrictMath.expm1() method:
Program 1:

## java

 `// Java program to illustrate the``// java.lang.StrictMath.expm1()``import` `java.lang.*;` `public` `class` `Geeks {` `public` `static` `void` `main(String[] args) {` `    ``double` `num1 = ``0.0``, num2 = -(``1.0``/``0.0``);``        ``double` `num3 = (``1.0``/``0.0``), num4 = ``32.2``;``    ` `    ``/*It  returns e^num - 1 */``    ``double` `eValue = StrictMath.expm1(num1);``    ``System.out.println("The expm1 Value of "+``                              ``num1+" = "+eValue);``    ` `    ``eValue = StrictMath.expm1(num2);``    ``System.out.println("The expm1 Value of "+``                              ``num2+" = "+eValue);``    ` `    ``eValue = StrictMath.expm1(num3);``    ``System.out.println("The expm1 Value of "+``                              ``num3+" = "+eValue);``    ` `    ``eValue = StrictMath.expm1(num4);``    ``System.out.println("The expm1 Value of "+``                              ``num4+" = "+eValue);}``}`

Program 2:

## java

 `// Java program to illustrate the``// java.lang.StrictMath.expm1()``import` `java.lang.*;` `public` `class` `Geeks {` `public` `static` `void` `main(String[] args) {` `    ``double` `num1 = ``2.0` `, num2 = -``51.8``;``        ``double` `num3 = ``61.0``, num4 = -``32.2``;``    ` `    ``/*It  returns e^num - 1 */``    ``double` `eValue = StrictMath.expm1(num1);``    ``System.out.println("The expm1 Value of "+``                              ``num1+" = "+eValue);``    ` `    ``eValue = StrictMath.expm1(num2);``    ``System.out.println("The expm1 Value of "+``                              ``num2+" = "+eValue);``    ` `    ``eValue = StrictMath.expm1(num3);``    ``System.out.println("The expm1 Value of "+``                              ``num3+" = "+eValue);``    ` `    ``eValue = StrictMath.expm1(num4);``    ``System.out.println("The expm1 Value of "+``                              ``num4+" = "+eValue);``}``}`

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