“PHP NAN” Ответ

PHP NAN

/*
NaN stands for Not a Number.

Impossible maths equation's output is NaN

PHP has a function to check if it is not a number.

is_nan()

the PHP var_dump() function returns the data type
*/

<?php
  $x = acos(8);
  var_dump($x);
?>
  
#This outputs NaN