Found this great download on Microsoft.com
DAX in the BI Tabular Model Whitepaper and Samples
This whitepaper and sample workbook introduce Data Analysis Expressions (DAX), a formula expression language used to define calculations in PowerPivot for Excel® workbooks and Analysis Services tabular model projects authored in SQL Server Data Tools.
This DAX in the BI Tabular Model file contains two files:
– Contoso Sample DAX Formulas.xlsx PowerPivot for Excel workbook
– DAX in the BI Tabular Model.docx whitepaper
The PowerPivot workbook illustrates the data analysis expressions (DAX) discussed in the included whitepaper.
The Contoso DAX Formula Samples file contains one file:
Contoso Sample DAX Formulas.xlsx PowerPivot for Excel workbook
NOTE: To fully interact with this sample, you must have Microsoft Excel 2010 and the Microsoft PowerPivot for Excel add-in installed or SQL Server 2012 Analysis Services instance running in Tabular mode and Visual Studio 2010 with SQL Server Data Tools installed.
Want to download it? Click here.