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15m
comment basic reproduction number of a simple SEIR-model
Just take the SEIR model and set $\mu = 0$.
23m
answered Solution of a Lambert W function
2h
answered general formula of a sequence
2h
comment How to solve Sturm-Liouville problem
The only difference between the problem you usually solve and this one is the $1+\lambda$? OK, so let $1+\lambda = \mu$, solve the problem with $\mu$, and then take $\lambda = \mu - 1$.
2h
comment Does the following converges?
A periodic function can't have a limit at $\infty$ unless it is constant.
2h
comment Every closed subset $E\subseteq \mathbb{R}^n$ is the zero point set of a smooth function
You don't need it to be locally finite: just choose the $c_j$ decaying rapidly enough that, with $f_j (x) = g(\|x - a_j\|/r_j)$, $|c_j | \|f_j^{(k)}\|_\infty < 2^{-j}$ for $k \le j$.
6h
comment Does the following converges?
A misleading hint, since there was no mention of "Cauchy Principal Value".
6h
comment Does the following converges?
Hint: the integrand is periodic.
7h
answered Let $2H=H+H=H-H$ and $H$ is non empty interior.why $H$ is a neighborhood of 0?
8h
revised Given a survival rate matrix, describe what can be said about it
added 212 characters in body
9h
answered Given a survival rate matrix, describe what can be said about it
9h
answered Is it possible to find the value of $x$ where $e^x$ exceeds $x^{10}$ by hand?
9h
answered Divergence of sum reciprocal of primes using Bertrand's Postulate
9h
revised What are the fixed points of $f_ c = c · \sin$ for $c > 1$?
added 119 characters in body
9h
answered What are the fixed points of $f_ c = c · \sin$ for $c > 1$?
10h
answered Curious about a made-up paradox
10h
comment What is the general skill to solve third order ordinary differential equation?
Is it linear? If not, do you have any reason to think it has a closed-form solution? Maybe it would be best to just tell us the actual equation.
13h
comment Integral of $\cosh^3(x)$
What more do you expect to do? You have the answer. Are you trying to convert it to an expression in sinh and cosh?
13h
answered What is the general skill to solve third order ordinary differential equation?
1d
answered Factorization $\cos(z) - \sin(z)$