Performance Tuning - will I loss the indexing when using derived table?

This was the question asked by a Developer when we are investigating a performance loss issues on a database. To the point a derived table means a virtual table that's calculated on the fly from a select statement. By default using derived tables can be tremendously useful in certain situations. In any case if you have 2 queries in hand say one with [ select C.address, C.area, B.productname, B.category, A.qty, A.price from order A join product B on A.productID = B.productID.... .] and another with...(<a href="http://sqlserver-qa.net/blogs/perftune/archive/2007/08/21/1625.aspx">read more</a>)<img src="http://sqlserver-qa.net/aggbug.aspx?PostID=1625" width="1" height="1">