Java Math.expm1() is a static method in the Java Math class that calculates e^x - 1, where e is Euler's number and x is the input. It is used in scientific calculations to improve precision for small values of x. Introduced in Java 2007 with Java 7, expm1() is particularly valuable in numerical computations that require accurate results for exponential functions.

https://docs.oracle.com/javase/8/docs/api/java/lang/Math.html