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 Feb 24 asked Does $\mid x-y\mid>0,x\neq-y$ imply $\mid\mid x\mid-\mid y\mid\mid>0$? Feb 21 accepted Is the integral of square of a function (with parameter) positive? Feb 20 asked Is the integral of square of a function (with parameter) positive? Feb 19 comment Integrate $I=\int_e^\infty\left(\frac{\log\log y}{y(y+1)}\right)^2dy$ using residue calculus? I actually meant from $1$, not $e$. My mistake. Feb 19 accepted Integrate $I=\int_e^\infty\left(\frac{\log\log y}{y(y+1)}\right)^2dy$ using residue calculus? Feb 18 comment Integrate $I=\int_e^\infty\left(\frac{\log\log y}{y(y+1)}\right)^2dy$ using residue calculus? Oh yes, sorry I missed that. Feb 18 comment Integrate $I=\int_e^\infty\left(\frac{\log\log y}{y(y+1)}\right)^2dy$ using residue calculus? Of course - the branch. I wonder If I could create a branch cut along the negative axis and use a half key hole contour... looking at the answer below I doubt it... Feb 18 comment Integrate $I=\int_e^\infty\left(\frac{\log\log y}{y(y+1)}\right)^2dy$ using residue calculus? Thanks for the detailed answer. Feb 17 asked Integrate $I=\int_e^\infty\left(\frac{\log\log y}{y(y+1)}\right)^2dy$ using residue calculus? Feb 17 comment Can one define a cross product for functions? If using the analogy with vectors, then maybe such a "cross product function" $c(x)\not\equiv0$ should have the property $$\int_{\mathbb{R}}c(x)(a(x)-b(x))dx=0$$ since for vectors $\mathbf{a}\cdot \mathbf{c}=\mathbf{b}\cdot \mathbf{c}=0$. If you could find such a $c(x)$ for given $a(x)$ and $b(x)$ then you are free to define it. Feb 16 comment How to approach this integration problem? Define "draw", "cute", and "bunny". Sorry, couldn't resist. Feb 16 revised How to solve this DDE: $f'(x-1)-f''(x)=g(x)$. added 3 characters in body Feb 16 revised How to solve this DDE: $f'(x-1)-f''(x)=g(x)$. edited title Feb 16 asked How to solve this DDE: $f'(x-1)-f''(x)=g(x)$. Feb 16 comment Evaluation of Bose-Einstein and Fermi-Dirac Integrals First thing I'd do is a change of variable $y=(p-\mu)/T$, because in the case of $e^y-1$ in the denominator you will probably end up with the Riemann zeta function $\zeta(\cdot)$. Not totally sure on that one, would have to perform the substitution to be sure, but see en.wikipedia.org/wiki/Riemann_zeta_function#Definition to see what I'm getting at. Feb 15 comment How to mathematically determine the number of odd numbers between two integers? $N_{\text{odd}}(x)=\lfloor (x+1)/2\rfloor$, where $\lfloor\cdot\rfloor$ is the floor function. Feb 12 revised Solving a delay differential equation added 136 characters in body; edited tags Feb 12 revised Solving a delay differential equation added 3 characters in body Feb 12 revised Solving a delay differential equation deleted 3 characters in body Feb 12 revised Solving a delay differential equation added 3 characters in body