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| bio | website | |
|---|---|---|
| location | ||
| age | ||
| visits | member for | 2 years, 6 months |
| seen | 8 hours ago | |
| stats | profile views | 88 |
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Jan 8 |
revised |
Topic for a high school-level math elective? edited title |
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Jan 8 |
asked | Topic for a high school-level math elective? |
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Dec 26 |
comment |
Arithmetic on $[0,\infty]$: is $0 \cdot \infty = 0$ the only reasonable choice? Note that the "useful proposition" that is given on the next page (namely "If $0 \leq a_1 \leq a_2 \leq \cdots$, $0 \leq b_1 \leq b_2 \leq \cdots, a_n \to a \text{ and } b_n \to b, $ then $a_nb_n \to ab$") only holds if $0 \cdot \infty$ is defined to be $0$. |
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Dec 24 |
comment |
Optimal algorithm for finding the odd spheres Do we know in advance whether the odd sphere is heavier or lighter than the others? |
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Dec 19 |
comment |
Set Theoretic Definition of Numbers You might find this "buzz" by Terence Tao useful: google.com/buzz/114134834346472219368/RarPutThCJv/… |
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Dec 19 |
awarded | Critic |
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Dec 17 |
comment |
Easy question about finite energy due to convergence @Fulwig: there are many ways to understand that identity, but I think the easiest is to note that the LHS is an infinite geometric series. Wikipedia has more: en.wikipedia.org/wiki/Geometric_series |
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Dec 16 |
answered | solving integral $\int{{3^x}{e^x}dx}$ |
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Dec 15 |
answered | Count of unique algebras with one unary operation (on finite set) |
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Dec 15 |
awarded | Supporter |
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Dec 15 |
answered | Do your friends on average have more friends than you do? |
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Dec 14 |
comment |
Why do we define quotient groups for normal subgroups only? This doesn't fix the problem. See Tobais's answer. No matter how we look at the group operation, it has to be independent of which coset representatives we choose. The problem is easiest to see if you just consider the product $(xh)(yh)$ like I do above, but expand Tobais's $(xy)H=(x'y')H$ and you'll still get a term like $y^{-1}hyh$ which needs to be in $H$. Therefore $H$ must be normal. |
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Dec 14 |
awarded | Teacher |
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Dec 14 |
answered | Why do we define quotient groups for normal subgroups only? |
