Talk:Cauchy-Schwarz Inequality

Revision as of 11:58, 9 April 2008 by JBL (talk | contribs) ("not really a proof": new section)

USAMO 1995 number 5 is a great problem solving example.--MCrawford 15:22, 18 June 2006 (EDT)

"not really a proof"

Any two vectors define a plane; in that plane, we can measure the angle between them, and CS is then equivalent to the fact that the cosine of this angle is less than 1 in absolute value. This is just as much a proof of CS (taking for granted some simple facts about the geometry of ${\bf R}^n$) as it is the reverse -- if you think these facts about ${\bf R}^n$ are "less basic" than CS, feel free to add a proof of CS using "more basic" things. --JBL 15:58, 9 April 2008 (UTC)