It returns the value of pi

<?php
echo pi();
?>

Output

3.1415926535898

It converts octal number to decimal

Example

<?php
echo octdec(11);
?>

Output

9

It  seed the better random number generator

Example

<?php
mt_srand(mktime());
echo(mt_rand());
?>

Output

254590754

It generates a better random value

Example

<?php
echo mt_rand(111,2222);
?>

Output

1787

It returns  largest possible random value

Example

<?php
echo mt_getrandmax();
?>

Output

2147483647

It returns lowest value

Example

<?php
echo min(10,11,17)
?>

Output

10

It returns maximum value

Example

<?php
echo max(10,11,17)
?>

Output

17

It returns natural logarithm

Example

<?php
echo log(17)
?>

Output

2.8332133440562

It returns log(1+x)

Example

<?php
echo log1p(1)
?>

Output

0.69314718055995

It returns  Base-10 logarithm value

<?php
echo log10(1);
?>

Output

0