Questions tagged [mathematica]
For questions concerning the popular computational software program published by Wolfram Research. (Note: you are more likely to get quicker and more accurate response if you ask the question on their user forum or on the Mathematica Stack Exchange site.)
733 questions
1 vote
2 answers
120 views
Finding specific points on a complex parametric curve [closed]
I work on the following equation $$ \frac{1}{z_1+z_3} = \frac{1}{z_1+z_2} + \frac{1}{z_1} + \frac{z_1}{z_2} + \frac{1}{(z_1+z_2)^2}. $$ Let $z_1$ and $z_2$ be given by $z_1=\frac{1}{2}\exp(i\alpha)$ ...
0 votes
0 answers
37 views
Why does $\lim_{x \to 0}a_n = -C_n(g(1/x))$?
Define the sequence of functions $a_n$ such that $a_0 = f(x)$ and $a_n = \int a_{n-1}dx$ if $n \geq 1$ and $f(x)$ is an analytic function. Then $\lim_{x \to 0}a_n = -C_n(g(1/x))$ for all $n \geq 0$ if ...
0 votes
0 answers
74 views
What is the Hausdorff dimension of this Cantor-like set?
Suppose $\alpha=\ln(2)/\ln(3)$. (This is the Hausdorff dimension of the Cantor set.) I originally assumed the Cantor-like set has Hausdorff dimension $\alpha$, but now I assume I’m incorrect. Here is ...
1 vote
0 answers
52 views
ROC for $\mathcal{L}_s[a^x]$ for $a \in \mathbb{R}$ && $a>0$
Question: What is the ROC (region of convergence) for the laplace Transform $\mathcal{L}_s[a^x]$ for $a \in \mathbb{R}$ && $a>0$ My attempt: $$\begin{align} \mathcal{L}_s[a^x] &= \int\...
0 votes
1 answer
36 views
Complex Integral Evaluation with complex conjugates and absolute values
I need some help solving this integral here. I am trying to run a code in Mathematica, but the running time is awfully long. Does anyone have any tips/tricks on how to do it faster? Any help is ...
3 votes
3 answers
241 views
Computing the real root of $\frac{(1-n)^{n-1}}{n^n}x^n+x-1 = 0$ analytically
I have the following trinomial equation $$ \frac{(1-n)^{n-1}}{n^n}x^n+x-1 = 0, $$ where $n=1-\frac{1}{m}$ and $m > 1$. I want to compute the single root of this equation by evaluating the ...
0 votes
2 answers
222 views
Justifying a closed-form integral derived by Mathematica
I was intrigued by this previously bountied question, which investigates the integral $$\int_{0}^{+\infty}\left[\frac{1}{\sqrt{1-e^{-t}}}\exp\left(\frac{2xye^{-\frac{t}{2}}-\left(x^2+y^2\right)e^{-t}}{...
1 vote
0 answers
104 views
Trigonometric integral problems related to hypergeometric function
I am dealing with two integrals: $$ \int \frac{\cos[(n+\frac{1}{2})x]}{\sin^{p+1/2}x}dx,\qquad \int \frac{\sin[(n+\frac{1}{2})x]}{\sin^{p+1/2}x}dx $$ where $n>p>0$, $n,p\in\mathbb{N}$. I have ...
0 votes
1 answer
129 views
Get different geographical distances on earth (modeled as ellipsoid)
Using Vincenty's formulae with $$P_{\text{Frankfurt}}=(50.11552, 8.68417)$$ $$P_{\text{Rio}}=(-22.9083, -43.1964)$$ and get the shortest geographical distance (World Geodetic System) $$s\approx 9564....
9 votes
3 answers
293 views
Is there any "nice" form of $\int_0^1 \frac{\ln(x+a)}{x^2+1} \mathrm{d}x$ ($a>0$)?
The result of $$\int_0^1 \frac{\ln(x+a)}{x^2+1}\, \mathrm{d}x$$ should be real for positive number $a$, but Mathematica always gives a result full of terms like $$\mathrm{i} \cdot \operatorname{...
0 votes
0 answers
63 views
Help visualise this problem from a math olympiad
My teacher told me to explain how I solved that problem to the class and I did, but some people can't understand the logic of adding the vectors and the rotations. Would it be possible for the "...
1 vote
1 answer
67 views
Findng a closed form expression for axially symmetric solutions in spherical coordinates with known infinite series Legendre polynomials
I have two infinite series of axially symmetric solutions in spherical coordinates $(r, \theta)$ , one series is expanded using the Legendre polynomials $ P_n (\cos\theta)$ , and the other series is ...
-1 votes
1 answer
192 views
In terms of performance, how to get a solution to this mathematica equation having large constants with y×67 being a perfect square?
Simple question, I’ve the following type of equation to solve in order to build the inputs parameters for an algorithm : ...
0 votes
0 answers
66 views
Define a function as the nth derivative of an infinitely differentiable function of n for all real numbers
Can we define a function $\alpha$ which is the $n^{th}$ derivative of some infinitely differentiable function $f(n)$ for all real $n$? That is, $\alpha(n) = \frac{d^n}{dn^n} (f(n)) = f^n(n)$. This ...
0 votes
0 answers
55 views
Calculating Jones polynomials for virtual links in mathematica
So, the KnotTheory package for Mathematica is advertised as working for classical links. But one can construct a PD code for a virtual link as well. Will this package correctly calculate the Jones ...