Java.lang.StrictMath.expm1() Method

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Description

The java.lang.StrictMath.expm1() method returns e^x -1. For values of x near 0, the exact sum of expm1(x) + 1 is much closer to the true result of e^x than exp(x).It include some cases −

• If the argument is NaN, the result is NaN.
• If the argument is positive infinity, then the result is positive infinity.
• If the argument is negative infinity, then the result is -1.0.
• 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.expm1() method

public static double expm1(double x)

Parameters

x − This is the exponent to raise e to in the computation of e^x -1.

Return Value

This method returns the value e^x - 1.

Exception

NA

Example

The following example shows the usage of java.lang.StrictMath.expm1() method.

package com.tutorialspoint;

import java.lang.*;

public class StrictMathDemo {

   public static void main(String[] args) {

      double d1 = 0.0 , d2 = -(1.0/0.0), d3 = (1.0/0.0);
   
      /*  returns (Euler's number e raised to the power of a double value)-1 
         i.e ex - 1  */

      double eulerValue = StrictMath.expm1(d1); 
      System.out.println("Value = " + eulerValue);
      eulerValue = StrictMath.expm1(d2); 
      System.out.println("Value = " + eulerValue);
      eulerValue = StrictMath.expm1(d3);
      System.out.println("Value = " + eulerValue);
   }
}

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

Value = 0.0
Value = -1.0
Value = Infinity