## How to find this kind of relationship: $x-\frac{1}{x}=A$ and $x+\frac{1}{x}=\sqrt{A^2-4}$?

Could someone explain how to get from: $$x-\frac{1}{x}=A$$ to $$x+\frac{1}{x}=\sqrt{A^2-4}$$ ?It is one of the Algebra II tricks.

Thanks.

## What kind of standard deviation must be used in optimization algorithms?

I would like to ask about the standard deviation of objective function value.

There are two types of standard deviations:

1. Population standard deviation

2. Sample standard deviation

In metaheuristic optimization algorithms most scholars are used std in your papers. What kind of standard deviation is used in metaheuristic optimization algorithms?

## Do wifi access points and routers get some kind of data from devices when a device is able to see them?

I was wondering if when a router is broadcasting its signal, it is able to handshake with devices that are wifi enabled and looking for a wifi network to connect and get some info from them?

## I’ll transate any kind of word french to english in cheap rate. for $5 I can translate any article from French to English. I speak both French & µEnglish very well and I’ve had a lot of experience translating, for me and for other people & I’ve gotten paid for it before, so this is not a first, you can count me for a professional wor by: Saimulhasan321 Created: — Category: Article Translating Viewed: 165 ## Choosing$r$things from a set containing$l$things of one kind,$m$things of a different kind,$n\$ things of a third kind,…

Here is a statement from a textbook that I’m referring to:

From a set containing $$l$$ things of one kind, $$m$$ things of a different kind, $$n$$ things of a third kind and so on, the number of ways of choosing $$r$$ things out of this set of objects is the coefficient of $$x^r$$ in the expansion of $$(1+x+x^2+x^3+…+x^l)(1+x+x^2+x^3+…+x^m)(1+x+x^2+x^3+…+x^n).$$

Can someone please explain the intuition behind this? How can it be derived?

## What kind of font(s) offer maximum on-screen readability for consumption on smartphones in Africa?

I know that Africa is very large and very diverse, a continent and not anything like a single country, and cell phone hardware is presumably not uniform.

However, if it is known, what kind of font(s) would be optimal for ebooks intended for consumption on smartphones in Africa?

## What kind of Visa (Russian Federation) do I need?

I’m traveling to Amsterdam and I have a valid Schengen Multi-Entry Visa. I have a layover in Moscow for 13 Hours and I want to explore the city during that time. Can anyone guide me what kind of Visa should I apply for whether a Transit Visa would be enough or I need to apply for Tourist Visa to VFS-Russia? I am an Indian Citizen. Thank you in advance for your assistance.

## How can i recognize what kind of wifi SoC that my phone using?

How can i recognize what kind of wifi SoC that my android smart phone using?

etc bcm…

and my smart phone can not access in dmesg. ㅜㅜ

## Does the Detect Evil and Good spell let the player know what kind of ground (consecrated or desecrated) they have found?

In D&D 5e, the detect evil and good spell states that:

For the duration, you know if there is an aberration, celestial, elemental, fey, fiend, or undead within 30 feet of you, as well as where the creature is located. Similarly, you know if there is a place or object within 30 feet of you that has been magically consecrated or desecrated.

To me, it’s unclear whether, if the caster detected some consecrated ground, it would be possible for them to mistake it for desecrated? Or vice versa? Do they just know that this ground has been touched by the gods, or specifically whether there were good or evil ones?

I’m not asking with regards to a specific situation that happened in play; I’m just curious how it should go as intended by the game writers.

## Ubuntu 19.04 background kind of pixelized

I have a problem with my Ubuntu background. It seems to get some kind of pixelized. I searched the internet but couldn’t find any solution. My background is the default background from Ubuntu 19.04.

Here is my desktop

The problem usually occurs after I put my notebook in hibernation mode. I recently installed bumblebee with nvidia drivers. Bumblebee is from the official repos and the drivers from the nvidia ppa.