# Function Reference

Tan

Calculates the tangent of a number.

Tan ( expression )

Parameters

expression | Value in radians.

Return Value

Returns the trigonometric tangent of number.

Remarks

1° = pi / 180 radians.
Note that Tan is "infinite" for ... -3PI/2, -PI/2, PI/2, 3PI/2, 5PI/2, ... and tends to return 1.63317787283838e+016 for such multiples of Pi-halves.

Related

Sin, Cos, ASin, ACos, ATan

Example

$pi = 3.14159265358979
$x = tan($pi / 4)
$degToRad = $pi / 180
$y = Tan(90 * $degToRad) ;tangent of 90°