# Tagged Questions

For questions related to usage of Wolfram Alpha.

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### Vertex Cosine Similarity of a weighted graph

I'm trying to calculate the vertex cosine similarity of a weighted directional graph, however struggling to understand the concept. While I understand the methodology for simple and directed graphs, ...
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### Wolframalpha, picturing sets

I have a short question. Is there a way to picture sets like $\{z+2\pi k+i, k\in\mathbb{Z}, z\in S^1\}\subset\mathbb{C}$ with wolframalpha, or any other online tool? Thanks in advance.
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### How to graph 3D functions of two variables on Wolfram Alpha?

How to graph this on wolfram, google, or other free software: \begin{alignat*}{3} x(s, t) &= a\cos(mt) \cos^{k}(ns) &&\cos(t) &&\cos(s), \\ y(s, t) &= a\cos(mt) \cos^{k}(ns) &...
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### Why does Wolfram show two different medians for this dataset?

If you enter these values into Wolfram: {18,21,13,19,24,17,14,12,15,14} In the Statistics output it shows a median of 16, which is correct. However, in the Box ...
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### Why is wolfram alpha plotting this differently?

I have an equation for a cylinder as $x^2+(y-b)^2=a^2$ for some $a$ and $b$. so I just plugged in $b=2$ and $a=1$ and tried to plot it using wolfram alpha, and the 3D plot looked like half a cylinder, ...
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### Integral of $\dfrac{1}{x\sqrt{x^2-1}}$

I am very confused by this. I know that the derivative of $\text{arcsec}(x)$ is $\dfrac{1}{|x|\sqrt{x^2-1}}$. However, if you plug in the integral of $\dfrac{1}{x\sqrt{x^2-1}}$ into wolfram alpha it ...
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### Plotting numbers in the complex plane using WolframAlpha

I read this article on understanding imaginary numbers as rotations of real numbers in the complex plane. Having read it, it's easy for me to see how the real number $1$ is simply a point on the real ...
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### Two variants of Radiality centrality

I am implementing Radiality centrality. For formula I am using definition from CentiScaPe: Network centralities for Cytoscape. I was doing some tests and I found some examples at Wolfram Alpha site. ...
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### use of wolfram in determining area between two curves

I am new to the use of Wolfram (that for the limited cases I have used is very impressive). However I wonder if anyone can tell me what I am doing wrong. I wanted to calculate the area between the two ...
81 views

### Is $x=0$ a local minimum of $f(x)=x^{2/3}(5-x)$?

It seems to be decreasing for values below zero and increasing for values between zero and 2. However $f'(0) = \frac{(-5 (x-2))}{3 x^{1/3}}|_{x=0}$ does not exist. So it's not a local minimum? Btw, ...
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### Problem Inputting Formula Into Wolfram Alpha [closed]

I am trying to calculate the following: $1-\sum_{k=0}^4\frac{\binom{2,500}{k}\binom{247,500}{8,500-k}}{\binom{250,000}{8500}}$ I am inputting this into wolfram alpha like this but I can't seem to ...
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### cubic root of negative numbers

Excuse my lack of knowledge and expertise in math,but to me it would came naturally that the cubic root of $-8$ would be $-2$ since $(-2)^3 = -8$. But when I checked Wolfram Alpha for $\sqrt[3]{-8}$, ...
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### PrimeQ[ Table[sum_(n=1)^(N)n!, {N,1,30}]]

The PrimeQ[Table[...]] command used to work in Wolfram|Alpha back in 2012 but now it doesn't give any answer. Is there a substitute?
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### Partial derivative of $\frac{d}{dx}(x^2-2sin(y))$

WolframAlpha computes $\frac{d}{dx}\left(x^2-2(\sin y)\right)$ to be $$\frac{d}{dx}\left(x^2-2 (\sin y)\right) =2 \left(x-(\cos y)y'(x)\right)$$ entered "differentiate (x^2 - 2*sin(y)) with ...
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### Two results for the same (?) derivative $f(x) = \frac{y}{x}$

I was looking for a method to differentiate $f(x) = \frac{y}{x}$. Entering "differentiate $f(x) = y/x$" into WolframAlpha gives result: $$f'(x) = \frac{-y}{x^2}$$ The main step of computing this ...
280 views

### Evaluation of the integral $\int_{-6}^{-3}\frac{\sqrt{x^2-9}}{x}$

How to evaluate the following integral? I have tried the following things but I have no idea to continue after the last step. Moverover, the integral seems wrong when compared with the ans from ...
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### Is wolframalpha wrong (Plotting inequalities)

I just wanted to plot a simple inequality: $$-x \geq 4$$ and wolframalpha gives me the following plot: But I think it should look like this: Am I correct? If so why is wolframalpha producing such ...
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### Integral of $-4\sin(2t - (pi/2))$ weird behavior on wolfram alpha

I'm confused by what Wolfram Alpha is doing with my function: $$-4\sin{(2t - (\pi/2))}$$ on why the it gets replaced by $$4\cos{(2t)}$$. Is it equal? Link: See behavior here
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### Solid has same volume when axis of rotation increases?

I'm working on calculating the volumes of different solids using integration. The problem I'm working on says to find the volume of two solids, one revolved around the line $x = 4$ and the other ...