Detailed explanation of the basic usage of cosh function in PHP

gitbox 2025-05-26

In PHP, cosh() is a built-in mathematical function for calculating hyperbolic cosines. Hyperbolic cosine function is widely used in many fields such as engineering calculation, graphic drawing, and physical modeling. This article will introduce in detail the basic syntax, usage methods and common application scenarios of the cosh() function.

1. Introduction to the cosh() function

The cosh() function returns the hyperbolic cosine value of the specified value. Its mathematical definition is:

 cosh(x) = (e^x + e^(-x)) / 2

In PHP, this function can be called directly and is part of the PHP core without introducing additional libraries or extensions.

2. Syntax format

 float cosh ( float $num )

$num : The floating point number of hyperbolic cosine needs to be calculated.
Return value: The hyperbolic cosine of this value, of type floating point.

3. Basic examples

Here is a simple example of usage:

 <?php
$num = 1.0;
$result = cosh($num);
echo "cosh($num) The value is: $result";
?>

The output result is:

 cosh(1) The value is: 1.54308063482

4. Use with graphic display

In some graphic drawing tools, such as when you need to render a catenary-like curve, cosh() can be used to calculate the y coordinates of each point in the path:

 <?php
for ($x = -5; $x <= 5; $x++) {
    $y = cosh($x);
    echo "x: $x, y: $y\n";
}
?>

This type of function is very practical when simulating natural sagging forms such as cables, suspension bridges, and chains.

5. Dynamic calls combined with URL parameters

Suppose you have a page that wants to dynamically calculate the value of cosh() based on the parameters in the URL, you can do this:

 <?php
if (isset($_GET['x'])) {
    $x = floatval($_GET['x']);
    $y = cosh($x);
    echo "cosh($x) = $y";
} else {
    echo "Please URL Input parameters x，For example：https://gitbox.net/cosh.php?x=1.5";
}
?>

This script can be deployed on the server, and users can obtain cosh() results corresponding to different input values by modifying URL parameters.

6. Things to note

The input value should be floating point type. Although integer types can also be passed in, the function will be automatically converted.
The return value is always positive because the hyperbolic cosine function image is always greater than or equal to 1.
If the input is too large, it may cause inaccuracy due to exponential overflow.

7. Summary

PHP's cosh() function is a practical and direct tool for processing computational scenarios involving hyperbolic functions. It can be seen in physical simulation, graphic design and mathematical modeling. Mastering its basic usage will help improve your ability in math operations. Using URL parameters can also improve the interactiveness and dynamicity of the application.

cosh