Math Trigonometric functions COS() to get cosine value of any radian as input in PHP

Calculate the cosine of an angle

cos() expects an angle in radians and returns its cosine.

$angle = deg2rad(60);
echo cos($angle); // approximately 0.5

The examples below build from the basic call to practical variations and edge cases.

<?Php
echo COS(PI()); // Output is -1
echo "<br>";
echo COS(PI()/2); // Output  6.1232339957368E-17 // Same as 0 
echo "<br>";
echo COS(PI()/3); // Output is 0.5
echo "<br>";
echo COS(PI()/4); // Output is 0.70710678118655 
?>

Syntax

cos(float $num): float;

The argument is an angle in radians. Use deg2rad() to convert degree values before calling cos().

deg2rad() with COS()

We can use deg2rad() to convert Degree value to radian and then use COS().

<?Php
echo cos(deg2rad(0)); // Output  is 1
echo "<br>";
echo cos(deg2rad(180)); // Output  is -1
?>

Example: Cosine of Large Values

echo cos(100000);  // Output: 0.9367521275331447

Example: Cosine in Physics (Force Calculation)

$angle = deg2rad(60);  // Convert degrees to radians
$force = 100;
echo $force * cos($angle);  // Output: 50 (Force in the x-direction)

Example: Cosine of 0 Degrees

$angle = 0;
echo cos(deg2rad($angle));  // Output: 1

Example: Cosine of 90 Degrees

$angle = 90;
echo cos(deg2rad($angle));  // Output: 6.1232339957368E-17 (close to 0)

Example: Calculating Cosine for Negative Angles

$angle = -45;
echo cos(deg2rad($angle));  // Output: 0.70710678118655

These examples cover the cosine function for various angles, including 0, 90 degrees, and negative angles.

Plotting of SIN & COS curves by using PHP GD function with deg2rad()

Math Functions SIN() function rad2deg() function

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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