Function of {

*x*∈ \(\mathbb{R}\) |*x*≠ \(\dfrac{π}{2}\) +*k*π, où*k*∈ \(\mathbb{Z}\)} in \(\mathbb{R}\) defined by \(f(x) = \dfrac{\sin (x)}{\cos (x)}\).### Notation

The tangent function is noted as “tan(*x*)” which is read as “tangent of *x*.”

Some English texts use the notation “tg(*x*).”