LOG(): The logarithm of a number to base

<?Php
echo LOG(2);// Output is 0.69314718055995
echo "<br>";
echo LOG(-1);// Output is NAN
echo "<br>";
echo LOG(0);// Output is -INF
echo "<br>";
echo LOG(5.7);// Output is 1.7404661748405
?>

LOG(X,Y);

LOG() with Base

<?Php
echo LOG(5,2);// Output is 2.3219280948874
echo "<br>";
echo LOG(5,10);// Output is 0.69897000433602 
echo "<br>";
echo LOG(5,2.7183);// Output is 1.609427153552
?>

Example: Calculating Logarithms with Different Bases

$value = 100;
$base = 2;
$log_base2 = log($value, $base);  // Output: 6.643856
echo $log_base2;

Example: Handling Invalid Inputs

$value = -10;
$result = log($value);
if (is_nan($result)) {
    echo "Logarithm undefined for negative values.";
}

Logarithm undefined for negative values.

Questions

Subhendu Mohapatra

Author & Instructor at plus2net

I write and maintain practical tutorials on Python, PHP, SQL, JavaScript, HTML, jQuery, and web development at plus2net. The tutorials focus on clear explanations, working examples, and code that readers can test and adapt while learning.

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