(PHP 4, PHP 5, PHP 7)
sqrt — 平锟斤拷锟斤拷
$arg
) : float
锟斤拷锟斤拷 arg 锟斤拷平锟斤拷锟斤拷锟斤拷
arg要锟斤拷锟斤拷牟锟斤拷锟�
锟斤拷锟斤拷 arg 锟斤拷平锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷时锟斤拷锟斤拷 NAN锟斤拷
Example #1 sqrt() 锟斤拷锟斤拷
<?php
// Precision depends on your precision directive
echo sqrt(9); // 3
echo sqrt(10); // 3.16227766 ...
?>