robjohn

West Hills, CA

none

Age: 56

the mean square The Mean Square
(with one standard deviation and several unusual ones)

aka Rob Johnson

$\LaTeX$ support for Chat

3h
revised Series about Euler-Maclaurin formula
add absolute values
20h
awarded Enlightened
20h
awarded Nice Answer
1d
revised Show $\int_0^1 \frac{\log(1-x)}{x}dx=-\frac{\pi^2}{6}$
extend the result
2d
answered Show $\int_0^1 \frac{\log(1-x)}{x}dx=-\frac{\pi^2}{6}$
2d
comment 2nd degree differential equation
To get more upvotes, consider this post.
2d
comment 2nd degree differential equation
The method to look up would be Integrating Factors.
Apr
29
answered 2nd degree differential equation
Apr
28
answered Calculate point coordinates from other points
Apr
27
answered arithmetic mean of smallest numbers of all subsets of r elements formed out of (1,2,..n)
Apr
26
revised Poisson distribution- mosquitos question
fix typo
Apr
26
answered Poisson distribution- mosquitos question
Apr
26
comment Is there an inequality for $\sinh(x)$ which is similar to this inequality $\cosh(x)\leq e^{x^2/2}$
Doh! Sorry about that.
Apr
26
revised Contour Integral of $\int\limits_0^{2\pi}\frac{d\theta}{1+a\cos\theta}$ for $a^2<1$ (textbook wrong?)
add a real method verification
Apr
26
comment Is there an inequality for $\sinh(x)$ which is similar to this inequality $\cosh(x)\leq e^{x^2/2}$
Related to cosh x inequality - Mathematics Stack Exchange:
Apr
26
revised Is there an inequality for $\sinh(x)$ which is similar to this inequality $\cosh(x)\leq e^{x^2/2}$
fix typo
Apr
26
answered Is there an inequality for $\sinh(x)$ which is similar to this inequality $\cosh(x)\leq e^{x^2/2}$
Apr
26
answered Contour Integral of $\int\limits_0^{2\pi}\frac{d\theta}{1+a\cos\theta}$ for $a^2<1$ (textbook wrong?)
Apr
25
comment Normal system of the least square method
I thought you were wondering why the factor of $2$ was not in the derivative of $\|Pa-y\|$. I didn't think you were concerned about the factor of $2$ in $2P^T(Pa-y)=0$ since $2x=0\iff x=0$. What is it that is bothering you about the factor of $2$?
Apr
25
comment Normal system of the least square method
@MarcZ: If the addendum does not answer your question, let me know.
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