## Find locations of all featured images of draft posts via SQL

I’m trying to get the file locations of all featured images used in draft type posts via SQL and phpmyadmin.

posts type attachment should hold the location of the image in the guid column.

SELECT voybp_posts.guid FROM voybp_posts WHERE voybp_posts.ID IN (     SELECT voybp_postmeta.meta_value     FROM voybp_postmeta     WHERE voybp_postmeta.post_id IN (         SELECT voybp_posts.ID         FROM voybp_posts         WHERE voybp_posts.post_status="draft")) 

This script should be good but its very complex and takes forever to execute, any way for me to simpplify it?

## Define a variable to satisfy $x^3 = -x$, then sum to find exponential

I’m wondering if it is possible to tell Mathematica that my non-commuting variable satisfies $$x^3 = -x$$ such that it can compute $$\sum_{n=0}^\infty \frac{(Ax)^n}{n!} = e^{Ax} = \cos A+ x \sin A$$ with the Sum function, where $$A \in \mathbb{R}$$

I’ve tried it with the NCAlgebra package but now if I compute

Sum[(x A)^n/n!, {n, 0, \[Infinity]}] 

nothing happens. Here A is commuting and x non-commuting.

I’m not hung up on the NCAlgebra package, any way to simplify the sum to elementary functions is appreciated. But fundamental to the solution has to be that I can tell Mathematica that $$x^3 = -x$$, because my real target is to see if Mathematica can rewrite a sum where I know that $$x^3 = -x + y$$ with known $$x$$ and $$y$$.

p.s. possible solutions of such variables would be a normalized Pauli vector $$\vec{\sigma}$$ or a vectorial quaternion.

## How one can find I am using virtual box Virtual Machine linux through Anydesk remote application?

I recently created a virtualbox virtual machine of Ubuntu 18.04 and installed Anydesk remote desktop app in it. An IT guy accessed my computers desktop via Anydesk app, but he is actually inside the Ubuntu Virtual Machine on Virtualbox. I don’t even mentioned anything about Virtualbox, but after asking me my laptop model and brand, in less than one minute he asked me “Are you using Virtualbox VM?”. I startled, he even mentioned which virtualization software I am using( virtual box) even there is VMWARE, Parallel, Nutanix and manymore. My host machine is Linux Mint. Can anyone explain how our IT guy managed to know that I am running Ubuntu 18.04 inside virtualbox as a Virtual Machine.

## Does Detect Magic allow players to find magical traps without a perception check?

Consider the following scenario: The party enters a room that appears to be a dead end, but in fact has a secret door with a magical trap on it. While standing in the room, a member of the party casts Detect Magic to see if there’s anything magical in the room.

Does the glow of the trap’s magical aura allow them to automatically locate it, without the need for a perception check? If not, does it grant a bonus of any kind on the perception check?

## Find the missing initial conditions for system of ODES

I want to solve the following system of ODEs:

   s1 (t) = -(k1*s1 *(k2*s2 + s3))/N,    s2 (t) = ((k1*s1 *(k2*s2 + s3))/N) - k3*s2,     s3' (t) = k3*s2 - k4*s3      s4' (t) = k4*s3 

where k1=0.4029;k2=0.7;k3=0.41;k4=0.182; N=s1+s2+s3+s4; my problem I don’t have initial conditions, is there any possible way in mathematica to find the initial conditions and solve the system?

Thanks

## How does a Pseudodragon interact with Find Familiar?

The Find Familiar spells allows a magic user to summon a spirit which takes on an animal form to serve as a familiar. If it is defeated, it disappears, and can be resummoned by casting the spell again.

The Pseudodragon is said to be sought out by mages, for it serves as a superior familiar if it can be befriended.

Does this mean that a mage can befriend a Pseudodragon, gaining a familiar, without having the Find Familiar spell?

Does the Pseudodragon have the same abilities (delivering touch spells, pocket dimension storage) as the familiar from Find Familiar?

If a Pseudodragon is killed, can it be brought back with Find Familiar, or is that exclusive to the ‘spirit’ familiar from the spell?

An acceptable answer would highlight what is specifically unique to the Pseudodragon familiar, if anything.

## Explain the equation to find the collaboration between neighbors in SOM in unsupervised learning

In kohonen SOM algorithm, the equation to find the collaboration is:

I know that LDist is the lattice distance and sigma is the standard deviation. I am just wondering why they are squared ? Can anyone help me to visualize the equation or explain to me what is going on in the above equation ?

## What are the available D&D 5e backgrounds, and where can I find them?

Similar to the possible races, official classes, and 4e backgrounds questions, what are official WotC-published backgrounds available for players, and which books/resources contain them?

By official, I mean that the backgrounds are available for Adventurers League Play. While other backgrounds from Unearthed Arcana or from other WotC sources outside the D&D team are of interest, please mention whether they’re considered official and sanctioned or not.

## Find longest path by number of edges, excluding cycles

I need to analyse a directed graph but I don’t know the name of the algorithm I would need to use. The graph has many cycles.

My desired behaviour is: given a graph source and graph sink, find the longest path by number of edges, excluding cycles.

By graph source, I mean a vertex with one or more edges to other vertices and no incoming edges, and the opposite for sink. If there’s better terminology, then please let me know about this.

By excluding cycles, this might entail not traversing an edge the process traversed previously.

Do you recognise this algorithm and could you tell me the name, please?