Class with trigonometric, inv. trigonometric, hyperbolic and inv. hyperbolic functions The static methods implement safe versions of the functions, trying to avoid under- or overflows, testing if key values are close to zero. More exactly if they are within [-epsilon, epsilon], where epsilon = 1E-15. This is code based on [PEAR's Math_TrigOp](http://pear.php.net/package/Math_TrigOp/), and compatible with PHP 5.3+ and PEAR2.