night owl
Reputation
1,170
Top tag
Next privilege 2,000 Rep.
Edit questions and answers
Badges
11 21
Newest
Impact
~141k people reached

• 0 helpful flags
• 386 votes cast

# 372 Actions

 Jul 30 suggested approved edit on Easy Fourier series example: where is my mistake? Jul 12 awarded Nice Question Jul 5 revised Solve inhomogeneous wave equation improved notation formatting Jul 5 suggested approved edit on Solve inhomogeneous wave equation Jul 5 revised Find a single-valued analytic branch of $\sqrt{z^2-1}$ in $\mathbb{C} \backslash [-1,1]$. fixed format Jul 5 suggested approved edit on Find a single-valued analytic branch of $\sqrt{z^2-1}$ in $\mathbb{C} \backslash [-1,1]$. Jul 5 comment Evaluating $\int\limits_{-\infty}^\infty {\exp(iax)\over1+ix}dx$ This looks like the Fourier Transform. Jul 5 revised Differentiation under the integral sign. improved formatting. Jul 5 suggested approved edit on Differentiation under the integral sign. Jun 30 revised Gauss-Hermite quadrature of $\cos(x)$ over infinity Improved Formatting Jun 30 suggested approved edit on Gauss-Hermite quadrature of $\cos(x)$ over infinity Jun 30 comment How to find the eccentricity of this conic? What level are you asking this question from,... is this a pre-calculus course? Just so the responses and terminology would be more appropriate for your level. If so, you might want to tag your question with pre-calculus or the related as well. Jun 30 comment Laplace transform of $1/t$ Or more simply: $t^n \stackrel{\mathcal{L}}{\Longleftrightarrow} \frac{n!}{s^{n+1}}$ without involving the gamma ($\:\Gamma\:$) function. Jun 28 comment Evaluation of these integrals @draks: Of course not :D, using a CAS. Is it possible to get polylog function by hand or recognize it from doing intergrals? I just thought this was a CAS algorithmic way of deducing the problem into a more complex answer using special functions, because an elementary table look up failed. So it resorted to special solution techniques. Although $\tan k$ is considered a simple function but not sure about hyperbolic tangent :) Jun 28 comment Evaluation of these integrals I get this for integral one: Not sure if equivalent to Norbet answers. $\int_0^p \! ktanh(\pi k)=-(1/24)(-\pi^2+12p^2\pi^2-24p\ln(1+exp(2p\pi))\pi-12polylog(2,-exp(2p\pi)))/(‌​\pi^2)$ Jun 28 comment Solving a complex integral Similar type of question from a $\mathbb{R}$ domain standpoint. math.stackexchange.com/questions/73250/… Jun 28 comment Fundamental solution of the wave operator Have a look here for starts: math.ucsd.edu/~lindblad/110b/l17.pdf math.ucsd.edu/~lindblad/110b/l18.pdf Jun 8 awarded Constituent Jun 8 awarded Caucus Apr 29 accepted Definition of Sinc function