--- layout: doc outline: deep lang: en-US --- # TANH function ## Overview TANH is a function of the Math and Trigonometry category that calculates the hyperbolic tangent of a number. ## Usage ### Syntax **TANH(number) => tanh** ### Argument descriptions * *number* ([number](/features/value-types#numbers), required). The hyperbolic angle whose hyperbolic tangent is to be calculated, expressed in radians. ### Additional guidance The formula for the hyperbolic tangent is: $$ \text{tanh(x)} = \dfrac{sinh(x)}{cosh(x)} = \dfrac{e^x-e^{-x}}{e^x+e^{-x}} $$ ### Returned value TANH returns a real [number](/features/value-types#numbers) in the range (-1,+1) that is the hyperbolic tangent of the specified hyperbolic angle. ### Error conditions * In common with many other IronCalc functions, TANH propagates errors that are found in its argument. * If no argument, or more than one argument, is supplied, then TANH returns the [`#ERROR!`](/features/error-types.md#error) error. * If the value of the *number* argument is not (or cannot be converted to) a [number](/features/value-types#numbers), then TANH returns the [`#VALUE!`](/features/error-types.md#value) error. * For some argument values, TANH may return a [`#DIV/0!`](/features/error-types.md#div-0) error. ## Details * The TANH function utilizes the *tanh()* method provided by the [Rust Standard Library](https://doc.rust-lang.org/std/). * The figure below illustrates the TANH function.
