Dell Computer Corporation has significant investment activities. The following items are from Dell's 2010 financial statements (amounts are in millions):

Short-term investments Long-term investments	$373 $781
Investment income	$134
Purchase of investments	$1,383
Sales of investments	$1,538
Change in unrealized gains (losses) on long-term investments, net	$6

Dell states that all debt and equity securities are classified as available-for-sale and are subject to an annual impairment test.

Where would you find each of the above items in Dell's financial statements?

What value (cost or fair value) would you expect the first two items on Dell's balance sheet to represent?

What are impairments, and how do they differ from unrealized losses on long-term investments?