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### Questions (34)

 15 Method of proof of $\sum\limits_{n=1}^{\infty}\tfrac{\coth n\pi}{n^7}=\tfrac{19}{56700}\pi^7$ 11 “Proof” that $1-1+1-1+\cdots=\frac{1}{2}$ and related conclusion that $\zeta(2)=\frac{\pi^2}{6}.$ 6 Why is Catalan's constant $G$ important? 6 A number $a$ is a square in $\mathbf{Q}$ if and only if it is a square in $\mathbf{R}$ and $\mathbf{Q}_p$ for all primes $p$ 4 Can the equation $f''(x)+cf'(x)+g(x)f(x)=0$ be solved for $f(x)$?

### Reputation (793)

 +5 Should a metric always map into $\mathbf{R}$? +5 Homomorphism between $SL(2,\mathbb{C})$ and the Lorentz group and choice of metric +20 Can the equation $f''(x)+cf'(x)+g(x)f(x)=0$ be solved for $f(x)$? +10 Binomial expansion, how to do them quickly?

 9 Binomial expansion, how to do them quickly? 5 How to find the indefinite integral $\int \frac{dx}{1+x^{n}}$? 3 What does “c” represent in this equation? $\frac{(x-h)^2}{a^2}+\frac{(y-k)^2}{b^2}=c$ 2 What is actually a Determinant?(the body is long but to understand my question pls read it) 2 Air friction question

### Tags (61)

 9 binomial-coefficients × 2 2 physics × 2 5 integration × 6 2 determinant 5 indefinite-integrals 2 systems-of-equations 3 conic-sections 2 matrices 3 geometry 1 ordinary-differential-equations × 6

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