The standard Trigonometric Tangent function is supported, generating TAN (expression) and returning a value of type float. When dragging a Tangent operator into a variable, the following tree element is created.
Variable Creation > Input > Variables: SQL Elements pane - Trigonometric > Tangent
Columns and/or other expressions can be moved into the (empty) branch of the tree. There are no special properties for the Tangent operator.