Does Canon EF 50mm f/1.8 II work with Canon 200D?
Can I use a EF lens with a EF-S camera?
I've just started using TikZ and need to create a simple triangle commutative diagram like this one.    The closest I've been able to get is this.   How do I get the h arrow to go from A2 to A3? Everything I've tried just causes errors.  Here's my current code:  \begin{tikzcd}[column sep=small] A \arrow{r}{i}  \arrow{rd}{g}    &amp; A3 \arrow{d}{h} \\     &amp; A2 \end{tikzcd} Questions on perfect squares I recently attended a test which ask me two question based on perfect squares; here they are:  $1.$ How many even perfect squares between $1000$ and $5000$ are divisible by both $5$ and $9$?  $2.$ Can there be a perfect square whose digits consists of exactly $4$ ones, $4$ twos and $4$ zeroes in any order?  I haven't done anything much on perfect squares so I was reluctant to attempt them during exams, although as I had some spare time after finishing the other questions, I tried thinking about the first problem and I noticed that only $3600$ seems to satisfy the conditions, which is correct, but I don't know how to get this mathematically? And for the second problem, I don't have any clue till now.  Unfortunately they haven't given me any solutions for the questions, nor any ideas as to how to solve them (mathematically)? Where are packages stored installed with APT in Ubuntu 16.04? I'm looking for a way of saying “having amorous affairs”. Ideally it should indicate a married man fooling around with younger women, and the expression should be informal, humorous, in low register but yet not rude. I am unable to figure out simple solution to add "Bookman Old Style"  as a main font in my latex document. I have used below line but does not give me required font.  \usepackage{bookman}   Could not find any Simple correct answer for this. Pl. suggest how to do it.  I am using windows, pdflatex.  thank you Challenges with Key with Gaps? I had a mistake with a trigger which resulted in errors in PostgreSQL 9.4.3 on x86_64-unknown-linux-gnu, compiled by gcc (Debian 4.9.2-10) 4.9.2, 64-bit.  Each time during the error, the primary key of SERIAL increased.  After fixing the bug, the table measurements is    measurement_id | measurement_size_in_bytes |             time               ----------------+---------------------------+-------------------------------               1 |                     77777 | 2015-07-14 18:29:56.858703+03               2 |                       888 | 2015-07-14 18:29:56.882552+03               3 |                       888 | 2015-07-14 18:30:15.505957+03               4 |                       888 | 2015-07-14 18:41:01.878106+03              39 |                     77777 | 2015-07-15 12:11:21.21391+03              40 |                     77777 | 2015-07-15 12:11:59.551973+03              41 |                     77777 | 2015-07-15 12:12:05.48982+03              42 |                     77777 | 2015-07-15 12:13:02.402053+03              43 |                     77777 | 2015-07-15 12:13:02.419412+03              44 |                       888 | 2015-07-15 12:13:02.434728+03          ...   where the amount of error statements has been 35 (= 39-4).  This jump in IDs may become a challenge later when I want to integrate this table with a partial index where order matters.   Table  CREATE TABLE measurements     (         measurement_id SERIAL PRIMARY KEY NOT NULL,         measurement_size_in_bytes INTEGER NOT NULL,         time TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,         CONSTRAINT no_duplicate_measurements UNIQUE (time)     );       What are the challenges of keys with gaps? How can I query the name of the current SQL Server database instance? It is a bit of a "chicken or egg" kind of query, but can someone dreamup a query that can return the name of the current database instance in which the query executes? Believe me when I say I understand the paradox: why do you need to know the name of the database instance if you're already connected to execute the query? Auditing in a multi-database environment.  I've looked at all the @@ globals in Books Online. "SELECT @@servername" comes close, but I want the name of the database instance rather than the server. it VS. this Vs. that How can I make ffmpeg be quieter/less verbose? By default ffmpeg sends a whole lot of messages to stderr: when built, how it was built, codecs, etc, etc, etc.  How can I make it quieter?  I've tried -v 0 (and -v 10 since the documentation just coyly says Set the logging verbosity level. with no indication of what the range of inputs is) -- still not quiet.  I've tried -loglevel quiet -- still not quiet.  I should mention, I'm looking for "quieter," not "no output ever".  If there's an error I want to see it, but I don't need to hear about ffmpeg's configuration every. single. time. Styling multi-line conditions in 'if' statements? Consider the closed interval $[0,1]$, there is $\frac{2}{3} \in [0,1]$ where $p=2$ and $q=3$. Similarly consider $[2,3]$, one can have $\frac{5}{2} \in [2,3]$ where $p=5$ and $q=2$. Does every interval of the form $[a,b]$, where $a,b \in \mathbb{R}$ contain a rational of this kind. If yes, how can we prove it? How to contact professors for PhD vacancies? I know many master's students who get an opportunity to talk to their potential PhD advisors well before applying. In most cases this opportunity is available by the professors with whom they worked for their master's. Moreover, there are many others who establish a contact with professors by mailing them and enquiring about PhD vacancies.   My questions are:   How important is knowing an advisor prior to applying for PhD?  Does an email interaction play a vital role when the department makes its admit decisions? If email contact is important, can a student send out mails to 2-3 professors (working in the same area) in case one of them does not bother to reply? To sum up, is applying of any use (especially in top universities) when you have no contacts and only your credentials to bank on? The interval [0,1] andd [3,5] are equivalent. Is my proof correct? What is the sum of non-real roots of the polynomial equation? Error: "To run a ssis package outside of sql server data tools you must install [send successful email] of Integration Services or higher." NOTE that the title of this qusetion is a verbatim error message specific to this user. The error message illustrates a bug in the dtexec application, which substitutes a user variable into the error message string. In this case, the standard message Standard E dition is replaced with send successful email.  The 'standard' error message would be :  Description: To run a SSIS package outside of Business Intelligence Development Studio you must install Standard Edition of Integration Services or higher.    Version SSIS 2012. Package was originally 2005 ver. Package on file system.  DB Engine / Agent on Host 1, SSIS on Host 2.  Execution from Host 2 runs successfully. Execution from Host 1 gives the error in the question subject. Saw , but engine and agent are installed on Host 1. Has anyone seen this? Google returns no results when searching on the exact error (subject line is exact, wording is odd in the error message).  Thank you! How do I get the title of a .pdf document to appear as the page title? Site Analytics header does not show the link to "traffic sources" when in that section I was seeing the Site Analytics page (/site-analytics)  (>25K users) and also  and found out that the header is not consistent:   When in history, the header shows "history | traffic sources" When in traffic sources, the header just shows "history"   Graphically: Some areas of the mesh are dark (Shadow artefacts) I've been modeling a hermit crab and I don't know why but some areas of the mesh are really dark on some spots, like the legs and the claws.   I hope you can help me fix it. From , page 209:     Dividends   Dividends are income paid by investments. Both bond funds   and stocks can  pay dividends. Bond fund dividends (the interest paid   by the individual  bonds in a fund) tend to be higher (as a percentage   of the amount you have  invested in a fund). When a dividend   distribution is made, you can receive  it as cash (which is good if   you need money to live on) or reinvest it into  more shares in the   fund. In either case, the share price of the fund drops to  offset the   payout. So if you’re hoping to strike it rich by buying into a bunch    of funds just before their dividends are paid, don’t bother. You’ll   just end up  paying more in income taxes.    It is talking about mutual funds.   I've never played with stocks.  However, I would like to know more about it.  Does the bold text imply the stock price will drop because of a company giving out a dividend? I have noticed that some users have taken it upon themselves to create  that allow you to see a user's rank (percentile) among SO developers.  I like this.  I was wondering if the owners of the website are planning something like this in the future?  If so, are you planning on making this by tag?  (I care less about where I rank when compared to developers of a different language).  What I'm looking for is something like this:  C#:      User is ranked #XX (Top XX %) ASP.Net: User is ranked #YY (Top YY %)