http://blogs.technet.com/heyscriptingguy/archive/2010/03/06/hey-scripting-guy-march-6-2010.aspx
The key to unlocking the ability of Windows PowerShell to create useful formulas is to leverage the static methods from the system.math class. You can easily see them by using the Get-Member cmdlet, as shown here:
PS C:\> [math] | Get-Member -Static | Format-Table name, membertype -AutoSize
Name MemberType
—- ———-
Abs Method
Acos Method
Asin Method
Atan Method
Atan2 Method
BigMul Method
Ceiling Method
Cos Method
Cosh Method
DivRem Method
Equals Method
Exp Method
Floor Method
IEEERemainder Method
Log Method
Log10 Method
Max Method
Min Method
Pow Method
ReferenceEquals Method
Round Method
Sign Method
Sin Method
Sinh Method
Sqrt Method
Tan Method
Tanh Method
Truncate Method
E Property
PI Property
Konstantin Vlasenko 