<html><body>echo is_nan(200) . "<br>";echo is_nan(acos(1.01));</body><!-- Mirrored from www.w3schools.com/php/phptryit.asp?filename=tryphp_func_math_is_nan by HTTrack Website Copier/3.x [XR&CO'2014], Mon, 27 Jan 2020 02:51:03 GMT --></html>