Use this query :
SELECT name AS [UDFName]
,create_date as [CreationDate]
,modify_date as [ModificationDate]
,type_desc as [FunctionType]
WHERE type_desc LIKE '%FUNCTION%'
ORDER BY [UDFName]
-- Displays a list of all the UDF's on the AdventureWorks database along with the creation date, modification date and function type.
Note: User-defined functions are either scalar-valued or table-valued. Table-valued functions are further classified as inline or multi-statement.
What is the difference between Scalar-Valued, Inline Table-Valued and Multi-Statement Table-Valued functions?
Scalar functions return a single data value using the RETURNS statement. Inline table-valued functions return the result set of a single SELECT statement whereas Multistatement table-valued functions return a table.
References : http://msdn.microsoft.com/en-us/library/ms186755.aspx