(PHP 4 >= 4.1.0, PHP 5, PHP 7, PHP 8)
expm1 —
Returns exp($num) - 1, computed in a way that is accurate even
when the value of number is close to zero
expm1() returns the equivalent to
exp($ computed in a way that is
accurate even if the value of num) - 1num is near zero,
a case where exp($ would be
inaccurate due to subtraction of two numbers that are nearly equal.
num) - 1
numThe argument to process
e to the power of num, minus one.