This information is part of the Modelica Standard Library maintained by the Modelica Association.
Trigonometric tangent function
Returns the tangent of u, with -∞ < u < ∞ (if u is a multiple of (2n-1)*pi/2, y = tan(u) is +/- infinity). Argument u needs to be an Integer or Real expression.
The tangent function can also be accessed as Modelica.Math.tan.
tan(3.14159265358979) = 0.0