Mar 09, 2009 01:38
Prove the inequality (ab + cd)^2 <= (a^2 + b^2)(c^2 + d^2) using Rule 1 & 2 (addition, subtraction, multiplication and division preserving the inequality)..
I have no idea how to prove this backawards :S The whole 'true if', find the condition for this to be true is confusing me, I have no idea what I am looking for..
It's awesome that it's due tomorrow too :(
p.s. god, I miss group theory and symmetries right now.
edit:
*FIXED* I had it half right was just confused about the lay out it would seem - 5 min well spent (that's how long it took to have it explained, maybe less). Maths is funny like that sometimes :P