PHP tan()

PHP tan(x) function calculates the tangent value of radian angle x.

<?PHP
	echo tan(M_PI);  //-1.2246467991474E-16
	echo tan(M_PI/2);  //1.6331239353195E+16
	echo tan(M_PI/4);  //1
?>

deg2rad() function can be used to convert degree to radian angle.

<?PHP
	echo tan(deg2rad(180));  //-1.2246467991474E-16
	echo tan(deg2rad(90));  //1.6331239353195E+16
	echo tan(deg2rad(45));  //1
?>

Tangent y=tan(x) Graph