Apple Inc.'s financial statements

I am confused on the trend analysis mostly where to start. Please Help.

Apple Inc. Apple Inc. designs, manufactures, and markets personal computers, mobile communication devices, and portable digital music and video players and sells a variety of related software, services, peripherals, and networking solutions. The Company sells its products worldwide through its online stores, its retail stores, its direct sales force, and third-party wholesalers, resellers, and value-added resellers. Your parents are considering investing in Apple Inc. common stock. They ask you, as an accounting expert, to make an analysis of the company for them. Apple's financial statements and 10-K file are provided. Instructions: (1) Concept review (a) In your own words, define "Revenues," Explain how revenues are different from "gains." (b) What is performance obligation and how is it related to revenue recognition? (c) In general, what incentives do managers have to make self-serving revenue recognition choices? (2) Make a 3-year trend analysis, using 2011 as the base year, of (1) net sales and (2) net income. Comment on the significance of the trend results. (3) What information outside the annual report may also be useful to your parents in making a decision about Apple? CONSOLIDATED STATKMTENTS OF OPERATIONS (th millions, ercopt number of sharen which ase reflected in thouasads and per stare amseriti) See accomparying Notet to Cossolidated rinucial stafersentr. (In milions) Soe accompanyiag Netes to Consolidated Financial Stateneats. CONSOLIDATED BALANCE SHERTS CONSOL.IDATHD STATEMENTS OT SIAREHOT DERSPQUTH CONSOLIDATED STATEMENTS OF CASH FLOWS (in millions)