424 reputation
411
bio website in.another.dimension
location Athens, Greece
age 46
visits member for 3 years, 6 months
seen Aug 6 at 19:40

Interests: math, programming and games, not necessarily in that order.


Feb
12
awarded  Civic Duty
Jan
12
awarded  Citizen Patrol
Nov
29
comment Can every proof by contradiction also be shown without contradiction?
@amWhy: You say "One of the advantageous to constructing direct proofs of propositions, when this is feasible, is that one can discover other useful propositions in the process. " I agree but proofs by contradiction (or rather, attempts to proofs) can also lead to wonderful discoveries (non-euclidean geometry comes to mind).
Nov
29
comment Can every proof by contradiction also be shown without contradiction?
+1 Great explanation. Can you emphasize the affirmative answer?: So there are statements that are provable by contradiction that are not provable directly.
Nov
2
comment Spatial Geometry - Hole in Sphere
And this question has the calculus solution: Given a solid sphere of radius R, remove a cylinder whose central axis goes through the center of the sphere.
Nov
2
comment Spatial Geometry - Hole in Sphere
@rschwieb: No, that's a "well"-known puzzle. The volume does not depend on the radius of the sphere.
Sep
24
comment How is $e^x$ read aloud?
I would vote that this question is off-topic for this site. Perhaps it would fit better at the English.SE one.
Aug
24
comment Theorems with an extraordinary exception or a small number of sporadic exceptions
@AsafKaragila: Of course your theorem is a fallacy. It fails for number 10.
Aug
5
revised Evaluate $\lim_{n\to \infty}(\frac{1}{n+1}+\frac{1}{n+2}+\cdots+\frac{1}{6n})$
edited body
Aug
5
answered Evaluate $\lim_{n\to \infty}(\frac{1}{n+1}+\frac{1}{n+2}+\cdots+\frac{1}{6n})$
Jul
20
comment Are there an infinite set of sets that only have one element in common with each other?
@Oltarus: Perhaps you can count them, to see if they are actually 50 - and not count on the manufacturer's word.
Jul
19
comment Are there an infinite set of sets that only have one element in common with each other?
A related question (about the same game) at Math.SE: What is the math behind the game Spot It? and at SO: What are the mathematical/computational principles behind this game?
Jul
19
comment What's behind Conway's Game of Life search algorithms?
@DariusGoad: It's not what many (or few) people think but what the Law says. The Terms of Service were written mostly caring about the Law. And while it may or may not be a good measure of maturity, it's very acccurate and provable.
Jul
9
awarded  Yearling
Jul
9
answered Minimum Tournament Required
Jul
9
comment Help find hard integrals that evaluate to $59$?
Is that $$\ln(x^2)$$ or $$(\ln x)^2$$ ?
Jun
8
awarded  Constituent
Jun
8
awarded  Caucus
Jun
2
awarded  Autobiographer
May
12
comment Probability involving unique group combinations
It's not at all clear what is being asked here. Please try to explain better.