PHP expm1() Function – Returns exp(number) − 1 with High Precision

The expm1() function in PHP returns exp(number) - 1, delivering accurate results even when the argument is near zero, where a direct calculation of exp(number) - 1 may lose precision.

Signature: float expm1(float $arg) Parameter: $arg – the number to be processed.

Return value:

The value of e raised to the power of $arg minus one.

Example:

<?php
echo expm1(1);
echo expm1(-1);
echo expm1(5);
echo expm1(10);
?>

Output:

0
1.718281828459
22025.465794807
120.51041751873