> ## Documentation Index
> Fetch the complete documentation index at: https://docs.firebolt.io/llms.txt
> Use this file to discover all available pages before exploring further.

> Reference material for TANH function

# TANH

Calculates the hyperbolic tangent of a provided value.

## Syntax

```sql theme={"theme":{"light":"css-variables","dark":"css-variables"}}
TANH(<value>)
```

## Parameters

| Parameter | Description                                                | Supported input types |
| :-------- | :--------------------------------------------------------- | :-------------------- |
| `<value>` | The value that determines the returned hyperbolic tangent. | `DOUBLE PRECISION`    |

## Return Type

`DOUBLE PRECISION`

`TANH` is defined for every real argument and returns a value in the open interval between -1 and 1.

## Example

The hyperbolic tangent of 0 is 0:

<div className="query-window">
  ```
  SELECT TANH(0) as result;
  ```

  | result <span>double</span> |
  | :------------------------- |
  | 0                          |

  <p><span>Rows: 1</span><span>Execution time: 5.21ms</span></p>
</div>

At `LN(2)` the result is exact — `SINH(LN(2)) / COSH(LN(2))`, or `0.75 / 1.25`:

<div className="query-window">
  ```
  SELECT TANH(LN(2)) as result;
  ```

  | result <span>double</span> |
  | :------------------------- |
  | 0.6                        |

  <p><span>Rows: 1</span><span>Execution time: 5.21ms</span></p>
</div>