PHP exp() Function

The PHP exp() function returns e raised to the power of specified number (e^x). Please note that e is the base of the natural system of logarithms, and its value is approximately 2.718282. In special cases it returns the following:

• 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 positive zero.

Syntax

exp(x)

Parameters

Return Value

Returns e raised to the power of specified number.

Example:

In the example below, exp() function is used to calculate e raised to the power of specified number.

<?php
echo "exp(-2) = ".exp(-2)."\n";
echo "exp(-1) = ".exp(-1)."\n";
echo "exp(0) = ".exp(0)."\n";
echo "exp(1) = ".exp(1)."\n";
echo "exp(2) = ".exp(2)."\n";
echo "exp(INF) = ".exp(INF)."\n";
echo "exp(-INF) = ".exp(-INF)."\n";
echo "exp(NAN) = ".exp(NAN)."\n";
?>

The output of the above code will be:

exp(-2) = 0.13533528323661
exp(-1) = 0.36787944117144
exp(0) = 1
exp(1) = 2.718281828459
exp(2) = 7.3890560989307
exp(INF) = INF
exp(-INF) = 0
exp(NAN) = NAN