If x, y and z are real numbers such that: x + y + z = 5 and xy + yz + zx = 3, what is the largest value that x can have ?

Years ago I heard rumours about the Cauchy-Schwarz Inequality (which, incidentally is occassionally called the Bunyakovskii Inequality) actually being the Pythagorean Theorem in disguise, and vehemently refused to believe it was true. No, I said, it can't be! They put that in maths texts for our children to read. And yet, oh my, here it is again.

I was similarly disheartened a while back when it was revealed that one of the supposedly non-Euclidian 4-vector space geometries could be shown to resolve not just to spherical coordinates but to the ordinary, everyday, garden variety sphere.

Even more surprising was that both could be purchased as term papers, available in three lengths, for immediate download to your printer, from a website I shall not divulge here.

Posted by CeeAnne on 2004-11-13 12:30:31