How to find the square root of a number in PHP

Use a PHP program to calculate and return the square root of a given number, so first you need to understand what the square root of a number is. The square root, also called the quadratic root, is expressed as [±√￣], among which the square root of a non-negative number is called an arithmetic square root. A positive number has two real square roots, which are opposites of each other, and a negative number has two conjugate pure imaginary square roots.

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Formula definition:

If a number x, it The square of is equal to a, that is, x²=a,

If the square of x is equal to a, then x is called the square root of a, that is, √a￣=x

as shown in the figure below.

# Now we will use PHP code examples to introduce to you the PHP method of finding the square root of a number.

The code example is as follows:

<?php

//PHP程序来计算并返回给定数字的平方根
function my_sqrt($n)
{
    $x = $n;
    $y = 1;
    while ($x > $y)
    {
        $x = ($x + $y)/2;
        $y = $n/$x;
    }
    return $x;
}

print_r(my_sqrt(16)."<br>");
print_r(my_sqrt(25)."<br>");

In the above code, we create a my_sqrt method and implement it with a while loop. Here we calculate the square root of 16 and 25.

The calculation results are shown in the figure below:

This article is an introduction to the method of finding the square root of a number in PHP. It is simple and easy to understand. In fact, it is also a flexible application of the basic knowledge of PHP algorithms. I hope it will be helpful to friends in need!

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