# Futurebasic/Language/Reference/log

< Futurebasic | Language | Reference

## LOGEdit

### SyntaxEdit

*naturalLog#* = **LOG**(*expr*)

### DescriptionEdit

Returns the natural logarithm of

. The natural logarithm uses the transcendental number "e" as its base. *expr*

always returns a double-precision result.
**LOG**

is the inverse of the **LOG**`EXP`

function. That is:

equals **LOG**(EXP(x))`x`

.

**Note:**
To find the logarithm of

for an arbitrary base *expr*`n`

, use this formula:

`theLog# = `

**LOG**(expr)/**LOG**(n)

### See AlsoEdit

`EXP; LOG10; LOG2`