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| bio | website | |
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| visits | member for | 1 year, 1 month |
| seen | yesterday | |
| stats | profile views | 232 |
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May 14 |
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Can a Accumulation Point be an Eigenvalue? In what space is 0 an accumulation point, and what is it accumulated by? Clearly, the zero operator is compact and has eigenvalue 0... |
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May 8 |
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Constructing Points I'm pretty sure we'll need a drawing to help you. |
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Apr 10 |
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Explaining why we can't “find” an antiderivative of $f(t) = e^{t^2}$. The "general formula for the roots of a polynomial"-problem was solved beautifully by Galois theory; is this problem equally elegantly solved? |
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Apr 2 |
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Can convergence be seen as a form of continuity? Oh, i'm sorry, /all/ topological spaces $Y$. I read "is there a toplogical space "Y" s.t....". My bad. |
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Apr 2 |
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Can convergence be seen as a form of continuity? 1) Take $Y=\{x\}$ |
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Mar 23 |
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How do I prove the following: $f(S\cup T) = f(S) \cup f(T)$ 1. please use latex for math notation. 2. what are your own thoughts? what is your definition of them being equal? |
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Mar 19 |
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How do i prove that the reduced row echelon form is unique? By "question", I meant your definition of being in reduced row echelon form. I meant that you never defined what it means for $B$ to be the rref of $A$. |
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Mar 19 |
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How do i prove that the reduced row echelon form is unique? You only defined the property of being in reduced row echelon form. This is a yes/no question. I cannot think of a natural definition for uniqueness from your question. |
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Mar 19 |
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to show $X$ is disconnected You don't need a concept of a "mother space" to define connectedness - it's all about finding two open subsets $A,B\subset X$ with $A\cap B=\emptyset$ and $A\cup B=X$. |
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Mar 19 |
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$g:\mathbb{C}\rightarrow\mathbb{C}$ be analytic and $g(0)\neq 0$ we need to calculate $\frac{1}{2\pi i}\int_{|z|=r>0} f(z)g(z) dz$ Calculate residue at 0 using Laurent series? |
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Mar 10 |
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Show that $f(z)$ has no antiderivative in $\,S=\mathbb{C}\setminus \{-i,i\}$ @mrf: Then i think it would be more correct to say "You could've also picked an integral around z=-i, because you'd get similar problems", instead of just "repeat". "Repeat" makes it sounds like they're both necessary. |
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Mar 10 |
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Show that $f(z)$ has no antiderivative in $\,S=\mathbb{C}\setminus \{-i,i\}$ In the third solution, the repetition for $z=-i$ is not necessary - you have already proven that the antiderivative does not exist in the given area. |
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Mar 10 |
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Show $I=\{sf\mid s\in \mathbb Z_{11}[x]\}$ matches $J=\{h \in \mathbb Z_{11}[x] \mid h(1) = h(-2) = 0\}$. @haunted85: Those are just the roots of $f$. |
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Mar 10 |
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Show $I=\{sf\mid s\in \mathbb Z_{11}[x]\}$ matches $J=\{h \in \mathbb Z_{11}[x] \mid h(1) = h(-2) = 0\}$. $f(\overline 2)=\overline 4$ so $f\not\in J$ but $f\in I$ with $s=1$. So $I\neq J$ |
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Mar 10 |
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Show $I=\{sf\mid s\in \mathbb Z_{11}[x]\}$ matches $J=\{h \in \mathbb Z_{11}[x] \mid h(1) = h(-2) = 0\}$. In the definition of $I$, don't you mean $s\in\mathbb{Z}_{11}[x]$? |
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Feb 9 |
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What is inverse of $I+A$? By substituting $A'=A-I$, you are basically asking for the inverse of all matrices. |
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Feb 6 |
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Example of an increasing, integrable function $f:[0,1]\to\mathbb{R}$ which is discontinuous at all rationals? @Belgi: that depends on your measure... |
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Jan 31 |
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A box contains 150 oranges.If one orange is taken… @AndréNicolas: I read it as a "factory of boxes" question, in which some process generates uniformly distributed rotten oranges. If you know the probability for this exact box, then apparently you have already counted the rotten ones. |
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Jan 31 |
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A box contains 150 oranges.If one orange is taken… Strictly speaking, we don't know the number of good oranges. There could be 150 bad oranges in the box. We can only give the estimated number of good oranges. |
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Jan 30 |
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Next number after 1729?? Of course, in Haskell, you wouldn't need to stop anywhere. You can just calculate them all and print a finite subset. |
