ereg_replace to remove all non-alphanumerics is skipping square brackets
Difference between regex [A-z] and [a-zA-Z]
Leg bisectors in a trapezoid and angle equality Let $PQRS$ be a trapezoid. The bisectors of legs $PS$ and $QR$ intersect the opposite legs at $M$ and $N$ so that triangles $PMS$ and $QNR$ are formed.  Prove that $\measuredangle PMS= \measuredangle QNR$.  The question may seem easy but I fail to move on, playing with angles didn't help. I'd appreciate some hint from somebody with an eye for geometry and triangles. Are there any rules on the positioning adverbs should take in a sentence? What is covered by CDIC savings deposit insurance? Why do different wavelength get impeded more or less when in different materials? Moving with the same speed, but a longer physical distance would imply that the fields oscillate less times in the material, but I don't know why a difference in the number of oscillations would impede the wave- I don't even know why things slow down in general. Why some electromagnetic wave would slow down just because it's entering other electromagnetic fields... It would seem to me that the only factor would be time taken to physically move some electron or something in the direction of the fields... But that seems to simple of an explanation to me. Deleted Partition Recovery I was installing ubuntu 12.04 on my system. There were 4 partitions on my system and I selected one of the four partition for the installation and chose the option of resizing the partition. Initially my partition was of size 100+GB and i created another partition out of it of size 15GB (EXT4). Now the moment I changed this partition structure my original partition got lost along with its data and I am left with 50GB partition and 50GB unallocated free space.   Now the data that I have lost is meant a lot to me and I want to recover that data. So is there any way I can recover it? And I haven't checked "format" option while resizing the partition. How to archive the whole website? To save a single page via Wayback Machine I can go to:      How can I archive the website recursively by Wayback Machine?    There is some project such as , but I'm looking for a feature which allows me the upload the website recursively. According to HTML specs, the select tag in HTML doesn't have a readonly attribute, only a disabled attribute. So if you want to keep the user from changing the dropdown, you have to use disabled.  The only problem is that disabled HTML form inputs don't get included in the POST / GET data.  What's the best way to emulate the readonly attribute for a select tag, and still get the POST data? What would you call someone who imposes on other people's generosity? What would you call someone who isn't afraid to ask for money or any kind of favor or who misinterprets someone's generosity for a consistent resource for what they need? I would like to clarify something that I don't think is clear in   The first automatic delete rule kicks in at 9 days for closed questions:     If the question was closed more than 9 days ago, and ...         was not closed as a duplicate   has a score of 0 or less   has no answers with a score > 0   some other criteria that don't matter right now...      Then, at 30 days, there's:     If the question is more than 30 days old, and ...         has −1 or lower score   has no answers   is not locked      This rule applies to both open and closed questions, but it doesn't mention the same exemption for duplicates.  I'm pretty sure that I've seen old, downvoted duplicates disappear on ServerFault (and that fits what the rule says), but I'm also sure I've seen lots of comments along the lines of  "duplicates aren't deleted."  So what I'm after is a clear statement from a power-that-be or a clear reference that says "duplicate questions fall under the same 30-day automatic deletion rule as any other question."  (or that they don't)  (Note: I realize this doesn't apply the stub left behind when a question is merged into another.  Those "stubs" are locked and are never deleted.) How to not have an equation in the first line using the align environment? Adding hyperlinks to pop-up data in qgis2web? Does anyone know if it is possible to add hyperlinks to image fields etc. in the pop-up windows of Qgis2web?  I've had a look in the layers javascript file, but the image source path isn't rendered using html, so I can't simply append &lt;a href" to it.  The image is coming in via the usual method of having a field that contains the path of the image file.  I'd like to achieve linking of the image, like in the example below. Alternatively, I could just populate the 'more info' field with the URL, but if I did that I'd like to avoid just doing it by having a field that contains the entire URL, as some may be quite long (these will only be internal links). Looking for a book with parallel universes like pages, possibly with "maze" in title, and a black Jewish female character Looking for a book. A series,  actually.  The main characters were a Jewish man and a black woman who was his wife. There was a running gag when she would tell people her last name and they thought it was unusual that a black woman would have a Jewish name.    They went on adventures in parallel dimensions. I believe that each book had a word repeated in the title, maybe "mirror?" Or "maze?" Or "page..."  it seems they jumped into worlds through a tool like a mirror or a book.   The parallel universes were like pages, and the pages closest to you were most similar but the further you got the further they were from your life.  One page over might be that you had something different for breakfast and so now you have a tummy ache, a few more pages over you might have become a prostitute, too far and it was theorized that humans had evolved differently altogether, I didn't get that far in the series.  For adults, and humorous.  I read them about 15 years ago, so they are not new. I would love to find them again. How to install TP-LINK Archer T4U driver? Is there a way to programmatically deactivate Proces Builder & flows? Is there a way to soql procesbuilder to tun activation off?  For example  List&lt;Processbuilder&gt; pbColl = new List&lt;Processbuilder&gt;();   Processbuilder pb=[SELECT status FROM Processbuilder WHERE status Active];  for(Processbuilder turnoff : pb){             turnoff.status = false;             pbColl.add(pb)} update pbColl;   If not is there a simple way to turn all activated Processes off/on? I am typing to get a sale amount (by input) to be multiplied by a defined sales tax (0.08) and then have it print the total amount (sales tax times sale amount).  I run into this error. Anyone know what could be wrong or have any suggestions?   salesAmount = raw_input (["Insert sale amount here \n"]) ['Insert sale amount here \n']20.99 &gt;&gt;&gt; salesTax = 0.08 &gt;&gt;&gt; totalAmount = salesAmount * salesTax  Traceback (most recent call last):   File "&lt;pyshell#57&gt;", line 1, in &lt;module&gt;     totalAmount = salesAmount * salesTax TypeError: can't multiply sequence by non-int of type 'float' Is there a Google Drive client available? Studying from Roman's Advanced Linear Algebra, I want to prove that $$U^* \otimes V^* \cong (U \otimes V)^* \cong \hom(U,V;\mathbb{F})$$ The author proves that $U^* \otimes V^* \cong (U \otimes V)^*$ by showing that there is an unique linear transformation   $$\theta:U^* \otimes V^* \to (U \otimes V)^*$$  defined by $\theta(f \otimes g)=f \odot g$ where $(f \odot g)(u \otimes v)=f(u)g(v)$  I want to prove that $U^* \otimes V^* \cong \hom(U,V;\mathbb{F})$. I tried to use the universal property by fixing $f \in U^*, g\in V^*$ and defining $S: U^*\times V^* \to \hom(U,V;\mathbb{F})$ as $S(f,g)=F_{f,g}$, where $F_{f,g}(u,v)=f(u)g(v)$, but I got stuck. How to create Unity indicators? I'm interested in Unity indicators and wonder if there is any tutorial on how to program them. I can use the sources of the existing ones as last resort, but I'd prefer a more friendly approach because my programming skills are quite limited. I was just curious, why is epic a silver badge if only 73 users have been awarded with it?  For example: Silver Epic - 73  Gold Electorate - 193    Edit: My point was to reduce the level of epic, like "hit the daily reputation cap on 30 days" so it becomes some what at par with other silver badges. Why is "letter" not plural in "two letter words"? Why is "letter" not plural in "two letter words"?  For me it's very strange as the equivalent in French would be plural but my English friend finds it totally normal.