Trevor Alexander
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 Apr21 awarded Popular Question Feb8 awarded Necromancer Jan30 awarded Yearling Dec22 awarded Constituent Dec9 awarded Caucus Jul2 awarded Curious Apr21 comment If there are obvious things, why should we prove them? Elitist much? I wonder how many grossly underpaid but otherwise mathematically apt people are down at walmart right now. (Including adjunct math faculty, even!) Apr18 comment Proving that the maximum of two convex functions is also convex Does this apply similarly for the maximum of two concave functions? Apr18 accepted Is a continuously differentiable function convex if all its partial second derivatives are non-negative? Apr9 comment Pizza theorem with realistic extension The proof sketch you gave requires that the crust be separable from the pizza, though. Apr3 comment Can a coin with an unknown bias be treated as fair? This is one of my favorite questions from Cover and Joy's info theory text book :) Feb13 comment Why are the rational numbers not continuous? I sort of get it from the wikipedia article: "An example of a set that lacks the least-upper-bound property is ℚ, the set of rational numbers. Let S be the set of all rational numbers q such that $q^2 < 2$. Then S has an upper bound but no least upper bound in ℚ: If we suppose p ∈ ℚ is the least upper bound, a contradiction is immediately deduced because between any two reals x and y (including √2 and p) there exists some rational p', which itself would have to be the least upper bound (if p > √2) or a member of S greater than p (if p < √2)." Feb13 comment Why are the rational numbers not continuous? one more question: when you say, "You've so just obtained ℝ!" here, does your argument assert that $\mathbb{Q}$ does not contain non-empty bounded above sets with a least upper bound? I'm having trouble understanding why not. Couldn't you just choose the largest element of a set contained in $\mathbb{Q}$ as its upper bound? I guess I'm really asking what situation yields a supremum not in $\mathbb{Q}$ but in $\mathbb{R}$. Feb12 comment Why are the rational numbers not continuous? Can you state briefly what the Archimedian property exactly is for completeness' sake? Feb9 comment Find integral when $dx$ is in the numerator So sick of that "non-standard" term tacked on to this significantly more intuitive interpretation. Feb3 comment What's a good class of functions for bounding/comparing ratios of complicated logarithms? That's a good one. Closer to home for me is visual/auditory senses, which give you great sensitivity at low ranges without causing a seizure when a truck passes :) Feb3 comment What's a good class of functions for bounding/comparing ratios of complicated logarithms? Geez, I should have seen that. My head was still spinning from the amount of algebra it took to get everything else out of the way. Thanks. Feb3 accepted What's a good class of functions for bounding/comparing ratios of complicated logarithms? Feb3 asked What's a good class of functions for bounding/comparing ratios of complicated logarithms? Feb2 revised I'm a teenager hoping to become a mathematician, but math isn't my forte. Is it possible? Removed erroneous accent mark on forte (the accented one is an unrelated musical term)