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04.03.2013 21:19
For all real numbers $a$ prove that $3(a^4+a^2+1)\geq (a^2+a+1)^2$
04.03.2013 21:20
here http://www.artofproblemsolving.com/Forum/viewtopic.php?f=188&t=523258
06.03.2013 01:39
Follow from Cauchy-Schwarz
01.09.2017 02:17
By C-S, $(1+1+1)(a^4+a^2+1) \ge (a^2+a+1)^2$.