As you know DAX, or Data Analysis Expressions, is the language of Power BI.
Knowing how to write DAX formulas is the key to creating expressive and advanced reports.it is such a useful part of advanced Power BI techniques. Microsoft have released on his power bi site a list of video tutorial to understand and use power bi DAX.
The videos are really full of information and very interesting i suggest you if you are new to this world to watch them. You can find:
- Introduction to DAX 9m
- DAX Calculation types 22m
- DAX Functions 17m
- Using variables in DAX expressions 4m
- Table Relationships and DAX 13m
- DAX Tables and Filtering 32m
Just Click one link and go to Learn!