2.13. Doing Trigonometry in Degrees, not Radians
$cosine = rad2deg(cos(deg2rad($degree)));
By definition, 360 degrees is equal to 2 radians, so it's easy to manually convert between the two formats. However, these functions use PHP's internal value of , so you're assured a high-precision answer. To access this number for other calculations, use the constant M_PI, which is 3.14159265358979323846.
2.13.4. See Also
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