## Exp Function

This standard VB function returns the value e (the base of natural logarithms) raised to a power.

##### Syntax

Exp(number)

Argument
Description

number

The exponent value for e

##### Returns

The value of e raised to the power number.

##### Usage

If the variable to contain the return value has a data type of integer, currency, or single, the return value is a single-precision value. If the variable has a data type of long, variant, or double, the value returned is a double-precision number.

The constant e is approximately 2.718282.

##### Example

This example estimates the value of a factorial of a number entered by the user. A factorial (notated with an exclamation mark, !) is the product of a number and each integer between it and the number 1. For example, 5 factorial, or 5!, is the product of 5*4*3*2*1, or the value 120.

Sub Button_Click
Dim x as Single
Dim msgtext, PI
Dim factorial as Double
PI = 3.14159
i: x = 55
If x< = 0 then
Exit Sub
ElseIf x>88 then
Goto i
End If
factorial = Sqr(2 * PI * x) * (x^x/Exp(x))
msgtext = "The estimated factorial is: " & Format _
(factorial, "Scientific")
End Sub