How Tanh() Works in PostgreSQL

In PostgreSQL, tanh() is a hyperbolic function that returns the hyperbolic tangent of its argument.

The argument and return value are provided as a double precision value.

Syntax

The syntax goes like this:

tanh(x)

Where x is a double precision value.

Here’s an example to demonstrate.

SELECT tanh(.5);

Result:

0.46211715726000974

Hyperbolic functions come from measurements made on a hyberbola.

Whereas the trigonometric functions relate to a circle, the hyperbolic functions relate to a hyperbola.

In mathematics, a hyperbola is basically two curves that are like infinite bows.

The following websites provide more information about hyperbola and hyperbolic functions: