Description
The cos() function calculates the cosine value of the number provided as its only parameter. The parameter should be passed as radians—you should use deg2rad() to convert degrees to radians.
$cos1 = cos(10); $cos2 = cos(deg2rad(80));
Syntax:
cos(float $num): float
Parameters
| Parameter | Description |
|---|---|
| num | An angle in radians |
Return Values
Returns the cosine of num in radians.
Examples
Example 1:
echo cos(M_PI);
Output:
-1
Example 2:
Calculate the cosine of a value:
$rad = pi() / 2; echo "The cosine of $rad = ", cos($rad);