bugs – FindMaximum showing unexpected behaviour

I am using FindMaximum to find the maxima and maximum value of a simple function sqrt{3-x^2} as follows:


I don’t get any answer and the code slowly consumes all my RAM (8 GB; usually it runs as about 3-4 GB) and just keeps on running. But, instead, if I modify the function to (3-x^2)^1 then the code runs and gives the expected {2., {x -> 1.}}.


So, I tried (3-x^2)^2 instead, thinking that the square root might be an issue but even this function just keeps on running forever and eats up all my RAM slowly. In fact any other power that tried just kept on running forever and slowly consuming all my RAM.

On the other hand if I try FindMaximum({(x^2-3)^(1/2),{1<x<4}},{x,4}) I get the expected {3.60555, {x -> 4.}}.

I am not sure what the issue is here. I have closed Mathematica, restarted my computer and stuff and this issue still persists. Every other code seems to be working as expected. Thanks.

magento2 – Applied Theme not showing on store

I have created 2 custom themes for the site, and applied one of theme as the theme store.
But my webpage/store is loading the layout of the theme which is not been applied. I have been struggling with this since 2 days, still no luck.

I have tried to modify the theme table from the db as well where I made all the types to 0. cleared caches n number if times, removed pub/static/frontend folder, Even if I delete the theme it is not loading the layout of the applied theme.

Anything which I have not tried yet?

magento version: 2.4.1

custom attributes value showing while exporting in customers grid : Magento 2.3.5

I Have two custom customer attributes , named old_customer(1=>Yes,0=>No) and zone(1=>India, 2=>UK, 3=>Others ) , both attributes is_used_in_grid is true . but while I’m exporting on to the customer gird exporting option I’ll get the result like below

Actual Result:

enter image description here

Expected Result :

enter image description here

Can someone please help me on this. Thanks in advance!!

Kali linux showing black screen in Virtual Box

I have downloaded .ova extension Kali linux for Virtual box and after importing it. It is showing only black screen when I launch the kali linux. I have done all methods I found on the internet but still I am meeting the same problem

algebraic topology – Showing the isomorphisms between two relative homology groups

I have been given that

$A subset mathbb{R}^n$ is a closed subset. Then the groups $H_i(mathbb{R}^n,mathbb{R}^n-A )$ and $H_{i+1}(mathbb{R}^{n+1},mathbb{R}^{n+1}-(A times {0}) )$ are isomorphic

Using this I am supposed to show that the following

If $A$ and $B$ are closed homeomorphic subsets of $R^{n}$, then $H_i(mathbb{R}^n,mathbb{R}^n-A )$ and $H_i(mathbb{R}^n,mathbb{R}^n-B )$ are isomorphic.

Note: I know that for closed homeomorphic subsets $A$ and $B$ , we have $H_i(mathbb{R}^n-A ) cong H_i(mathbb{R}^n-B )$. But I am not supposed to use that. I am going to prove $H_i(mathbb{R}^n-A ) cong H_i(mathbb{R}^n-B )$ using the problem above, using long exact sequence for pairs.

I wonder what is the main motive to move to higher dimension? I think we will be able to find open sets to use excision. I tried applying excision, but looks like I am not able to get the required subspaces.

Now how else can I attempt this problem?

syntax – Repeated For Loop on Different Inputs Showing Same Results

I ran the same For Loop on different input data and faced the problem that the result lists were all identical, despite the input data being different, as shown in the image below (network1 and network2 are different datasets). I presume I am making a technical mistake, if anyone could help me out I’d greatly appreciate it.

Evl( ) is the For Loop command

First set:

Evl1 = Evl;

Second set:

Evl2 = Evl;

Basically organised in this order and tried plotting histograms of Evl1 and Evl2 which gave identical graphs that they shouldn’t.

filemanager – there a way or setting for better and bigger thumbnails in the file manager? especially when not showing

is there a way in ubuntu 20.10 to see bigger and or better thumbnails of pictures in the file manager? Especially if your’re uploading pictures as a photographer.

enter image description here

in the picture you’ll see what I mean. its to small and when I choose a picture, no thumbnails appear on the right. sometimes they do, but its a struggle. you have to go back and check the file name to make sure its correct.

CURDATE(), now(), sysdate() showing yesterday’s date when run in Mysql

CURDATE(), now(), sysdate() all of them are showing yesterdays date which is causing to show wrong results in the system.

Below is the screenshot for the query in MySQL and its result
query and result

Can someone indicate as to why this is happening?

Why some emails dragged to a tab not showing in Gmail?

My Gmail is provided by my college’s G-Suite. I have just subscribed to a newsletter using this email account. I dragged these emails to a Socials tab, then made the Socials tab appear on the Gmail homepage. But when I click on the Socials tab, it doesn’t show these emails. It shows the other Google Classroom emails on Socials though. I have to click on Socials on the sidebar to make these newsletter emails appear.

I tried dragging them to Promotions too, still doesn’t work. But when I click on that tab from the sidebar it shows? Why does this happen? Is there a workaround? Is there any other way to add them to different tabs besides dragging? Something that’ll make it work?

I tried the option of “Move To” to Promotions, but still doesn’t show up. When I do “Move To Inbox”, only then they show up. What am I missing here?

What is this Inbox? There’s no tab for Inbox.

Also, how to automatically have all emails from this sender be sent to my Promotions tab? And show up too?

security – Google showing places I haven’t been

No. Your location history is never completely exact. It is because GPS location is often bad, particularly in these cases:

  • If you are inside reinforced concrete buildings or trains. It is because the metal in wall (of the building) or the case of the train shadows the signal of the GPS satellites.
  • If there is no GPS signal, google maps tries to use the MAC address of the available Wifi APs what your mobile can see – and compare it to the GPS signal of other google users, whose GPS at that position worked. It works in many cases, sometimes it does not (for example, the Wifi AP is actually another telephone of another Google Maps user who shares its mobile network with it).

If you see your position history (timeline) on the google, it shows you all the cities what the google thinks, you visited.

If the Wifi-based localization worked 10000 times in your life correctly, and 3 times badly, then you will see 3 cities where you never were. It does not matter that it worked correctly 9997 times, the first what you will think that you were never in Z├╝rich or Philadelphia.

Your position timeline overweights the mistakes of the google localization. You can see these false points, many of them are airports or train stations.

Probably there are some option to change your google maps timeline retroactively.