# Mathematical functions - logarithmic

These functions all operate on numeric expressions only, and will return an error if used on any other values. See also Mathematical operators.

Functions:

## 1. e()

`e()` returns the base of the natural logarithm, `e`.

Syntax: `e()`

Returns:

 A Float.
Query
``RETURN e()``

The base of the natural logarithm, `e`, is returned.

Table 1. Result
e()

`2.718281828459045`

1 row

## 2. exp()

`exp()` returns `e^n`, where `e` is the base of the natural logarithm, and `n` is the value of the argument expression.

Syntax: `e(expression)`

Returns:

 A Float.

Arguments:

Name Description

`expression`

A numeric expression.

Considerations:

 `exp(null)` returns `null`.
Query
``RETURN exp(2)``

`e` to the power of `2` is returned.

Table 2. Result
exp(2)

`7.38905609893065`

1 row

## 3. log()

`log()` returns the natural logarithm of a number.

Syntax: `log(expression)`

Returns:

 A Float.

Arguments:

Name Description

`expression`

A numeric expression.

Considerations:

 `log(null)` returns `null`. `log(0)` returns `null`.
Query
``RETURN log(27)``

The natural logarithm of `27` is returned.

Table 3. Result
log(27)

`3.295836866004329`

1 row

## 4. log10()

`log10()` returns the common logarithm (base 10) of a number.

Syntax: `log10(expression)`

Returns:

 A Float.

Arguments:

Name Description

`expression`

A numeric expression.

Considerations:

 `log10(null)` returns `null`. `log10(0)` returns `null`.
Query
``RETURN log10(27)``

The common logarithm of `27` is returned.

Table 4. Result
log10(27)

`1.4313637641589874`

1 row

## 5. sqrt()

`sqrt()` returns the square root of a number.

Syntax: `sqrt(expression)`

Returns:

 A Float.

Arguments:

Name Description

`expression`

A numeric expression.

Considerations:

 `sqrt(null)` returns `null`. `sqrt()` returns `null`
Query
``RETURN sqrt(256)``

The square root of `256` is returned.

Table 5. Result
sqrt(256)

`16.0`

1 row