PHP Challenges: Compute and return the square root of a given number

PHP Challenges - 1: Exercise-8 with Solution

Write a PHP program to compute and return the square root of a given number.

Input : 16

Explanation :

Sample Solution :

PHP Code :

<?php
// Function to calculate the square root of a number using the Newton's method
function my_sqrt($n)
{
    // Initialize variables $x and $y
    $x = $n;
    $y = 1;

    // Loop until $x is greater than $y
    while($x > $y)
    {
        // Update $x and $y according to Newton's method
        $x = ($x + $y) / 2;
        $y = $n / $x;
    }

    // Return the calculated square root
    return $x;
}

// Test the my_sqrt function with different inputs and print the results
print_r(my_sqrt(16)."\n");
print_r(my_sqrt(14)."\n");
?>

Explanation:

Here is a brief explanation of the above PHP code:

• The code defines a function named "my_sqrt()" which calculates the square root of a number using Newton's method. It takes a single parameter '$n', which is the number for which the square root is to be calculated.
• Inside the function:
• It initializes two variables '$x' and '$y' with initial values of '$n' and 1 respectively.
• It enters a "while" loop that continues until "$x" is greater than "$y".
• Within each iteration of the loop, it updates the values of "$x" and "$y" according to Newton's method for finding square roots.
• After the loop, it returns the calculated square root "$x".
• Function Call & Testing:
• The function "my_sqrt()" is called twice with different input values (16 and 14).
• The results of the function calls are printed using print_r(), which displays the calculated square root for each input value.

Sample Output:

4                                                           
3.7416573867739      

Flowchart:

PHP Code Editor:

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