1. The problem statement, all variables and given/known data Thread title 2. Relevant equations Cauchy inequality: [PLAIN]http://eom.springer.de/c/images/c020/c020880/c0208801.png [Broken] ak, bk are complex numbers 3. The attempt at a solution SPOILER ALERT: I'm trying to show linear dependence on a, b. Yes, I Googled "Cauchy equality hold" and came up with that. [PLAIN]http://i701.photobucket.com/albums/ww13/jamin2112/screen-capture-1-35.png [Broken] Kinda stuck now. Any suggestions?