How long is it okay to marinate pork ribs for?
How long is it safe to marinate meat?
The model used to open the store is incompatible with the one used to create the store How can I trigger a command when a player is hit by a Snowball? I am trying to make a snowball that triggers a command when it hits a player in 1.15, but I don't know how to do that. When I do execute at @e[type=snowball] run gamemode spectator @a[distance=..2] it only runs the command if it goes right next to them. Sugar daddy wants my online banking login info to make deposits — is it a scam? Someone is offering to pay me in a sort of sugar daddy/sugar baby arrangement. They want to make online deposits to me, and they're asking me for my online banking username and password. Is that information alone enough for them to be able to take my money out of my account, or am I safe? Suppose that sequences of real numbers satisfy:  \begin{align*}   a_n &amp;= \sum\limits_{r=0}^n \binom{n}{r} b_r \\ \end{align*}  Prove that:  \begin{align*}   (-1)^n b_n &amp;= \sum\limits_{s=0}^n \binom{n}{s} (-1)^s a_s \\ \end{align*}  My work:  The $n=0$ case:  \begin{align*}   a_0 &amp;= b_0 \\   b_0 &amp;= a_0 \\ \end{align*}  Then $n=1$ case:  \begin{align*}   a_1 &amp;= \binom{1}{0} b_0 + \binom{1}{1} b_1 = b_0 + b_1 \\   -b_1 &amp;= \binom{1}{0} a_0 - \binom{1}{1} a_1 = a_0 - a_1 \\   b_1 &amp;= a_1 - a_0 = b_0 + b_1 - a_0 = b_1 \\ \end{align*}  The inductive step:  \begin{align*}   (-1)^{n+1} b_{n+1} &amp;= \sum\limits_{s=0}^{n+1} \binom{n+1}{s} (-1)^s a_s \\ \end{align*}  I'm not sure where to go from here. I tried substituting $a_s$ into that last equation and it didn't help. Any ideas? When using the Stack Exchange App for Android, I encountered a problem when uploading multiple images to the same post.  After uploading a single image, the image Markdown is inserted normally, e.g.:  ![enter image description here][1]     [1]: http://i.stack.imgur.com/Cbh1m.jpg   As I upload more images, the list of URLs at the bottom of the post should be appended to. After uploading the above in a new post, I tap to place the cursor at the end of the first line, enter a newline and the toolbar reappears. I then upload a second image with this result:  ![enter image description here][1] ![enter image description here][2]     [1]: http://i.stack.imgur.com/Cbh1m.jpg   [2]: http://i.stack.imgur.com/V5nXV.jpg   Now I edit the image descriptions, to make sure I can keep track of all my images, place the cursor at the end of the second line and enter a newline. The edit box contains:  ![a black circle of utter blackness][1] ![the best planet earth clip art ever][2]      [1]: http://i.stack.imgur.com/Cbh1m.jpg   [2]: http://i.stack.imgur.com/V5nXV.jpg   I then upload a third image. What's interesting is that as the screen reloads, for an instant I see the best planet earth clip art ever replaced by more image markup, so the second line is this:  ![![enter image description here][2]][2]   But only for a moment. Then the screen updates, and the edit window is left in this state:  ![the best planet earth clip art ever][2] ![the best planet earth clip art ever][2] ![enter image description here][3]     [1]: http://i.stack.imgur.com/Cbh1m.jpg   [2]: http://i.stack.imgur.com/V5nXV.jpg   [3]: http://i.stack.imgur.com/6Ra5w.jpg   I correct the first line and insert a line break after the third line in preparation to upload the first image again (I really love blackness). Before uploading, the edit window looks like this:  ![a black circle of utter blackness][1] ![the best planet earth clip art ever][2] ![a fast computer][3]      [1]: http://i.stack.imgur.com/Cbh1m.jpg   [2]: http://i.stack.imgur.com/V5nXV.jpg   [3]: http://i.stack.imgur.com/6Ra5w.jpg   After uploading:  ![a fast computer][3] ![the best planet earth clip art ever][2] ![a fast computer][3] ![enter image description here][4]      [1]: http://i.stack.imgur.com/Cbh1m.jpg   [2]: http://i.stack.imgur.com/V5nXV.jpg   [3]: http://i.stack.imgur.com/6Ra5w.jpg   [4]: http://i.stack.imgur.com/ILUCC.jpg   Now, instead of adding a newline, I position my cursor at the end of the third line. The toolbar isn't visible so I insert a space and then delete it. I upload another copy of the third image from this position adjacent to other image markdown, and now the result is:  ![a fast computer][3] ![the best planet earth clip art ever][2] ![a fast computer][3]![enter image description here][4] ![enter image description here][4]      [1]: http://i.stack.imgur.com/6Ra5w.jpg   [2]: http://i.stack.imgur.com/V5nXV.jpg   [3]: http://i.stack.imgur.com/6Ra5w.jpg   [4]: http://i.stack.imgur.com/jG0fk.jpg   [5]: http://i.stack.imgur.com/ILUCC.jpg   Notice:   The new image, the fifth I have uploaded, goes in as image [4]. Not a problem, so far, but: The previous image description is still linked to image [4], now a different URL; and The first URL in the list has been overwritten by the URL of the third image, which happens to be immediately adjacent on the line where I inserted the most recently-uploaded image.   Reproduced at the time of this question revision, with the following specs:   Device: Moto G 2013 OS version: 4.4.4 App version: 1.0.57 Cannot deserialize instance of time from VALUE_STRING value This question attempts to collect a community-maintained list of quality books on the  programming language, targeted at various skill levels.  C is a complex programming language that is difficult to pick up on-the-go by reading online tutorials. A comprehensive book is often the best way to learn the language, and finding a good book is the first step. It is important to avoid badly-written books, and even more importantly, books that contain serious technical errors.  Please suggest edits to the accepted answer to add quality books, with an approximate skill level and a short blurb/description about each book. (Note that the question is locked, so no new answers will be accepted. A single answer is being maintained with the list)  Feel free to debate book choices, quality, headings, summaries, skill levels, and anything else you see that is wrong. Books that are deemed satisfactory by the C community here will stick around on the list; the rest will be regularly removed.  For books that have reviews by the Association of C and C++ Users (ACCU), a link to those reviews should be added along with the book.  See also:   Other C-related resources in the   A similar list for :      This question was discussed on  as part of the .The consensus was to keep it undeleted and actively maintained. How big is my single pattern in Photoshop I pulled a repeating pattern from someone else's PSD. Is there a way to figure out the size of the original pattern? I need to create an image with only one tile. Do I cast the result of malloc? Triangle inequality for L2 norm I am posed with a problem as below.  Let $X$ be the collection of real valued functions that are measurable on $[0,1]$. For a given number $p\geq 1$ define the $L^p$ norm by $(\int_0^1|f(x)|^p)^\frac{1}{p}$.  I need to show for $p=1,2$ that this defines a semi norm on $X$. $p=1$ was simple as was all of $p=2$ except for the triangle inequality. I am having trouble proving the triangle inequality for this. Could anybody nudge me into the right direction or am I simply over thinking it? I think I can prove it for vectors but I'm not sure how to tackle it with integrals. Right now I can only use relatively basic results because this in for an introductory measure theory course.  Thanks! Related posts display randomly by tag I would like to ask that what code should i add in order to make my related posts by tag to display randomly? I got this code from somewhere else.  &lt;?php $orig_post = $post; global $post; $tags = wp_get_post_tags($post-&gt;ID); if ($tags) { $tag_ids = array(); foreach($tags as $individual_tag) $tag_ids[] = $individual_tag-&gt;term_id; $args=array( 'tag__in' =&gt; $tag_ids, 'post__not_in' =&gt; array($post-&gt;ID), 'posts_per_page'=&gt;5, // Number of related posts that will be shown. 'caller_get_posts'=&gt;1 ); $my_query = new wp_query( $args ); if( $my_query-&gt;have_posts() ) { echo '&lt;div id="related"&gt;&lt;h4&gt;Related Posts&lt;/h4&gt;'; while( $my_query-&gt;have_posts() ) { $my_query-&gt;the_post(); ?&gt; &lt;div class="ncc"&gt; &lt;h5&gt;&lt;a href="&lt;? the_permalink()?&gt;" rel="bookmark" title="&lt;?php the_title(); ?&gt;" rel="nofollow"&gt;&lt;?php the_title(); ?&gt;&lt;/a&gt;&lt;/h5&gt; &lt;?php the_excerpt(); ?&gt;  &lt;/div&gt;&lt;!--ncc--&gt;  &lt;? } echo '&lt;/div&gt;&lt;!--related--&gt;'; } } $post = $orig_post; wp_reset_query(); ?&gt;   Any solution? Thanks! Can anyone explain reverse bias pn junction using only electrons as charge carriers In forward bias condition p-type semiconductor is connected to positive side and ntype semiconductor to negetive side and the electrons flow from n-type to p-type to cathode of battery.  But imagine the same situation when the situation is reverse biased so now p-type is connected to negetive terminal of battery and n-type to positive terminal of battery.  Now there is excess of electrons in n-region and it is connected to positive terminal of the battery.So electron can flow from n-type region to positive terminal of the battery due to potential difference created by battery whereas in p-type electrons can flow from one covalent bond to another as they do in forward biasing.  Only difference is,here electron move in opposite direction (from one covalent bond to another) i.e. from n-region to depeletion region whereas in forward bias they move from depeletion to n-region.Which shouldn't be a problem   Now in this manner current must flow regardless of biasing so what's the correction? What is the difference between currying and partial application? I quite often see on the Internet various complaints that other peoples examples of currying are not currying, but are actually just partial application.  I've not found a decent explanation of what partial application is, or how it differs from currying. There seems to be a general confusion, with equivalent examples being described as currying in some places, and partial application in others.  Could someone provide me with a definition of both terms, and details of how they differ? Is there a reason why ls does not have a --zero or -0 option Why three-phase power? Why not a higher number of phases? Is there a reason, beyond historical reasons, that three phases has become the dominant number of phases?  I am aware of the advantages against one phase and two phase, namely the reduced amount of conductor needed, and that motors can provide torque when stalled (and less pulsation).  Is this solely due to diminishing returns, with only a small increase in smoothness of torque application, at the cost of increased complexity (increased number of wires (albeit of smaller CSA)).  To be clear, the phases are all evenly distributed, that is, five phases separated by 72 degrees. Vandermonde identity corollary $\sum_{v=0}^{n}\frac{(2n)!}{(v!)^2(n-v)!^2}={2n \choose n}^2$ I am trying to prove this identity:  $$\sum_{v=0}^{n}\frac{(2n)!}{(v!)^2(n-v)!^2}={2n \choose n}^2$$ I think this identity (corollary of Vandermonde identity): $${n\choose 0}^2+{n\choose 1}^2+{n\choose 2}^2+\cdots+{n\choose n}^2={2n \choose n}$$ is applicable for solving it. Please give me some hints. thank you I have to prove by induction that $$\sum_{r=0}^{n}\begin{pmatrix}n \\ r \end{pmatrix}=2^k$$, using the identity $\begin{pmatrix}n \\ r-1 \end{pmatrix}+\begin{pmatrix}n \\ r \end{pmatrix}=\begin{pmatrix}n+1 \\ r \end{pmatrix}$. I'm fine with everything except the inductive step, where I only managed to get as far as $$\sum_{r=0}^{k+1}\begin{pmatrix}n \\ r \end{pmatrix}= \sum_{r=0}^{k}\begin{pmatrix}n \\ r \end{pmatrix}+\begin{pmatrix}n \\ k+1 \end{pmatrix}$$ I tried to then use the identity and substitute $\begin{pmatrix}n \\ r \end{pmatrix}=\begin{pmatrix}n+1 \\ r \end{pmatrix}-\begin{pmatrix}n \\ r-1 \end{pmatrix}$ but all this did was just take me around in a circle. I also couldn't substitute $2^k$ for $\sum_{r=0}^{k}\begin{pmatrix}n \\ r \end{pmatrix}$ since this didn't properly simplify to give $2^{k+1}$. However, I think that I have to obtain the expression $\sum_{r=0}^{k}\begin{pmatrix}n \\ r \end{pmatrix}$ since it simplifies to $2^{k+1}$. But I've not been able to obtain this in anyway so I'm wondering if anyone can guide in what I need to or what direction I need to take to complete the inductive step. I have a dataframe with many observations and many variables. Some of them are categorical (unordered) and the others are numerical.  I'm looking for associations between these variables. I've been able to compute correlation for numerical variables (Spearman's correlation) but :   I don't know how to measure correlation between unordered categorical variables. I don't know how to measure correlation between unordered categorical variables and numerical variables.   Does anyone know how this could be done? If so, are there R functions implementing these methods? Is $R^2$ useful or dangerous? If you are not satisfied with answers on someone else's question, should you ask your own? Suppose you had a question, and you really want a good answer that would solve your problem, but noticed it was already asked by someone else. Now, a lot of answers had been posted and upvoted, and maybe one was accepted. However, none of the answers solved your problem. The system does not promote the question very much because it is not considered "unanswered", and a lot of users who would otherwise bother to give a correct answer will probably skip the question completely as there are already many highly-voted answers.  Now, what should you do in this case?  One idea is to ask a new, completely identical question, but now you're in control to decide when it is answered. But would that go against SE policy?