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| bio | website | |
|---|---|---|
| location | West Hills, CA | |
| age | 54 | |
| visits | member for | 1 year, 10 months |
| seen | 4 hours ago | |
| stats | profile views | 5,580 |
The Mean Square
(with one standard deviation and several unusual ones)
aka Rob Johnson
Where would math be if Fermat had Post-it notes?
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Sep 10 |
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Proving that $A\subset B \implies \hat A \subset \hat B$ You're thinking too hard. |
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Sep 10 |
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Proving that $A\subset B \implies \hat A \subset \hat B$ @BenjaLim: I have been trying to find a hint that is not a full answer. It is not easy. |
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Sep 10 |
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Proving that $A\subset B \implies \hat A \subset \hat B$ hide the conclusion |
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Sep 10 |
reviewed | Approve suggested edit on equal ranks for symmetric matrices of the form $A = P^tBP$? |
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Sep 10 |
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Integral question: zeroes of the primitive. @mick: I was more trying to draw attention to being polite than how to improve the answer. You could just as easily have described what you had done (this can be very important) and then asked, "how should I proceed?" |
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Sep 10 |
answered | Uniform convergence problem for sine function |
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Sep 10 |
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Finding $\lim_{x\to +\infty}\big[\frac{x}{x+1}\big]^x$ Usually, "at infinity" means "in the limit" since there is not really an infinity in $\mathbb{R}$. What is true is that $\left\lfloor\frac{x}{x+1}\right\rfloor=0$ for all $x>0$ so $\lim\limits_{x\to+\infty}\left\lfloor\frac{x}{x+1}\right\rfloor=0$ even though $\lim\limits_{x\to+\infty}\frac{x}{x+1}=1$. |
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Sep 10 |
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Integral question: zeroes of the primitive. @mick: I'm sure what you meant was "@RobertIsrael: thank you for your answer. Would you please provide some more details along these lines?" There is no way that someone answering your question knows how much you know, and given this, Robert's answer is quite reasonable. After politely explaining what you have tried, I'm sure that Robert would be inclined to expand his answer. |
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Sep 10 |
reviewed | Approve suggested edit on Definite integral involving e and ln |
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Sep 10 |
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what is the fourier series of $x(at)$ when $a = 0, a>0$ or $a<0$? How do I go about solving this? fix answer |
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Sep 9 |
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what is the fourier series of $x(at)$ when $a = 0, a>0$ or $a<0$? How do I go about solving this? handle negative $a$ |
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Sep 9 |
answered | what is the fourier series of $x(at)$ when $a = 0, a>0$ or $a<0$? How do I go about solving this? |
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Sep 9 |
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Accuracy from approximating $\zeta(2)$ with a partial sum Yes, because the EMS formula terminates for polynomials. More generally, I showed in this answer that if the Fourier transform of a function is supported within $[-1,1]$, then the EMS formula converges for that function. |
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Sep 9 |
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Prove that $x^2 + 5xy+7y^2 > 0$ for all $x,y \in\mathbb{R}$ Another approach differing from the usual "complete the square" approach. |
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Sep 9 |
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Prove that $x^2 + 5xy+7y^2 > 0$ for all $x,y \in\mathbb{R}$ It's nice to see something different than the usual "complete the square" approach. |
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Sep 9 |
reviewed | Approve suggested edit on Prove that $x^2 + 5xy+7y^2 > 0$ for all $x,y \in\mathbb{R}$ |
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Sep 9 |
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Accuracy from approximating $\zeta(2)$ with a partial sum For the exponent $2$, I did this very thing in this answer. |
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Sep 9 |
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Accuracy from approximating $\zeta(2)$ with a partial sum @Henry: nice. Add that to your answer and undelete it :-) |
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Sep 9 |
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Accuracy from approximating $\zeta(2)$ with a partial sum I was going to use this method, but I was too slow. :-) |
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Sep 9 |
answered | Accuracy from approximating $\zeta(2)$ with a partial sum |
