Stack Exchange

robjohn

West Hills, CA

http://none

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

aka Rob Johnson

$\LaTeX$ support for Chat

top accounts reputation activity favorites subscriptions
Top Questions
Top Answers
513
How to prove that $\lim\limits_{x\to0}\frac{\sin x}x=1$?
math.stackexchange.com

172
What's 4 times more likely than 80%?
math.stackexchange.com

136
Slice of pizza with no crust
math.stackexchange.com

119
How to prove that $\frac{\zeta(2) }{2}+\frac{\zeta (4)}{2^3}+\frac{\zeta (6)}{2^5}+\frac{\zeta (8)}{2^7}+\cdots=1$?
math.stackexchange.com

115
Parabola is an ellipse, but with one focal point at infinity
math.stackexchange.com

95
Is it possible to represent every irrational number as a (limit of) an infinite sum of rational numbers?
math.stackexchange.com

80
Arc length contest! Minimize the arc length of $f(x)$ when given three conditions.
math.stackexchange.com

80
Proving an alternating Euler sum: $\sum_{k=1}^{\infty} \frac{(-1)^{k+1} H_k}{k} = \frac{1}{2} \zeta(2) - \frac{1}{2} \log^2 2$
math.stackexchange.com

78
Is there any integral for the Golden Ratio?
math.stackexchange.com

71
Can an infinite sum of irrational numbers be rational?
math.stackexchange.com

71
Computing $\zeta(6)=\sum\limits_{k=1}^\infty \frac1{k^6}$ with Fourier series.
math.stackexchange.com

64
Is it possible to write a sum as an integral to solve it?
math.stackexchange.com

61
Evaluating $\int_0^\infty \sin x^2\, dx$ with real methods?
math.stackexchange.com

58
A closed form of $\int_0^\infty\frac{\sqrt[\phi]{x}\ \arctan x}{\left(x^\phi+1\right)^2}dx$
math.stackexchange.com

56
Why is $i^3$ (the complex number “$i$”) equal to $-i$ instead of $i$?
math.stackexchange.com

54
Why does $1+2+3+\cdots = -\frac{1}{12}$?
math.stackexchange.com

54
How to evaluate $I=\int_0^{\pi/2}x^2\ln(\sin x)\ln(\cos x)\ \mathrm dx$
math.stackexchange.com

52
Coin flipping probability game ; 7 flips vs 8 flips
math.stackexchange.com

52
Curious Integral Proof
math.stackexchange.com

51
How to prove a trigonometric identity $\tan(A)=\frac{\sin2A}{1+\cos 2A}$
math.stackexchange.com

49
Evaluating $\lim\limits_{n\to\infty} e^{-n} \sum\limits_{k=0}^{n} \frac{n^k}{k!}$
math.stackexchange.com

49
Trivial zeros of the Riemann Zeta function
math.stackexchange.com

49
Find the simplest counterexample against exchanging limit and summation
math.stackexchange.com

48
Why can the complex conjugate of a variable be treated as a constant when differentiating with respect to that variable?
math.stackexchange.com

48
Generalized Euler sum $\sum_{n=1}^\infty \frac{H_n}{n^q}$
math.stackexchange.com

47
Linear diophantine equation $100x - 23y = -19$
math.stackexchange.com

46
How do you prove Gautschi's inequality for the gamma function?
math.stackexchange.com

46
How many lists of 100 numbers (1 to 10 only) add to 700?
math.stackexchange.com

45
Infinite Series $‎\sum\limits_{n=2}^{\infty}\frac{\zeta(n)}{k^n}$
math.stackexchange.com

44
I have a problem understanding the proof of Rencontres numbers (Derangements)
math.stackexchange.com

1 2 3 4 5 … 10