# Log Function

Returns a **Double** specifying the natural logarithm of a number.
**Syntax**
**Log(***number***)**
The required *number*argument is aDouble or any validnumeric expression greater than zero.
**Remarks**
The natural logarithm is the logarithm to the base *e*. Theconstant *e* is approximately 2.718282.
You can calculate base- *n* logarithms for any number *x* by dividing the natural logarithm of *x* by the natural logarithm of *n* as follows:
Log *n(x)* = **Log** ( *x* ) / **Log** ( *n* )
The following example illustrates a custom **Function** that calculates base-10 logarithms:

```
Static Function Log10(X)
Log10 = Log(X) / Log(10#)
End Function
```

## Example

This example uses the **Log** function to return the natural logarithm of a number.

```
Dim MyAngle, MyLog
' Define angle in radians.
MyAngle = 1.3
' Calculate inverse hyperbolic sine.
MyLog = Log(MyAngle + Sqr(MyAngle * MyAngle + 1))
```