Current Location: Home> Latest Articles> The difference between cosh and cos in PHP

The difference between cosh and cos in PHP

gitbox 2025-05-28

In PHP, cosh and cos are two commonly used mathematical functions. They seem to have similar names, but their functions and application scenarios are obviously different. Understanding the difference between these two functions will help developers choose the right tool when dealing with mathematical calculations.

1. Function introduction

  • cos($x) : calculates the cosine value of the angle $x$, where $x$ is an angle in radians.

  • cosh($x) : Calculate hyperbolic cosine value, where $x$ is a real number.

2. Mathematical definition

  • Cosine function:

cos ? x = e i x + e ? i x 2 \cos x = \frac{e^{ix} + e^{-ix}}{2}

  • Hyperbolic cosine function:

cosh ? x = e x + e ? x 2 \cosh x = \frac{e^x + e^{-x}}{2}

The difference is that the cosine function is a periodic function and is defined on a unit circle, while the hyperbolic cosine is a combination of exponential functions and is not periodic.

3. PHP sample code

The following code example demonstrates how to use cos and cosh functions respectively.

<code> <?php // Calculate the cosine value of the angle (radian) $angle = pi() / 3; // The radian corresponding to 60 degrees $cosValue = cos($angle); echo "cos(60°) = " . $cosValue . "\n";

// Calculate hyperbolic cosine value
$x = 1.0;
$coshValue = cosh($x);
echo "cosh(1) = " . $coshValue . "\n";

// For more mathematical function references, you can visit https://gitbox.net/manual/en/function.cosh.php
?>
</code>

4. Typical application scenarios

  • The cos function is widely used in geometry, physics, signal processing and other fields, and is used to calculate the periodic changes related to angles.

  • The cosh function is common in hyperbolic function problems in the fields of mathematics and engineering, such as calculating catenary lines, thermal conduction, etc.

5. Things to note

  • The input parameters of the trigonometric function in PHP are all radian systems. If you need to calculate with angle, you need to convert them first:

<code> <?php $degrees = 60; $radians = deg2rad($degrees); echo cos($radians); ?> </code>

  • When using cosh , the parameters are directly real numbers without angular conversion.

Understanding the difference between cos and cosh can help you avoid logical errors during development and select appropriate functions to complete accurate calculations.

Related