Math What does it mean to characterize a function? [on hold] By admin October 24, 2016 October 24, 2016 I am asked to characterize all functions for which a certain statement is true. How do you “characterize” a function? The statement is: There exists a b>0b > 0 such that for all ϵ>0\epsilon > 0, for all xx, |x| Prove that Q(√2)={a+b√2|a,b∈Q}\mathbb{Q}(\sqrt{2})=\{a+b\sqrt{2}|a,b\in \mathbb{Q}\} Weakly amenable Banach algebras