How do I center an element within a div without knowing the child element's width? I have this div that has a width of 100% and a height of 90px. Inside the div I have a img that is 90px in height, but I let the width set itself. So how do I set the img withing the div, without knowing it's width?
How to horizontally center an element How can I horizontally center a &lt;div&gt; within another &lt;div&gt; using CSS? &lt;div id=&quot;outer&quot;&gt;   &lt;div id=&quot;inner&quot;&gt;Foo foo&lt;/div&gt; &lt;/div&gt;
When I compile with LuaLaTeX and TL2016 this MWE   \documentclass{article}  \usepackage[no-math]{fontspec} \usepackage{luatex85} \usepackage{shellesc}  \setmainfont{Minion Pro}  \begin{document}  \huge{huge} \textbf{\huge{huge}}  \Huge{Huge} \textbf{\Huge{Huge}}   \end{document}   I have this .pdf.     Any help? With TL2015 all is correct. Thanks Is it possible to enter Russia by train 1-1.5 hours before the visa validity period starts? A friend of mine is taking the Train from Finland to Russia. She has now paid and sent the Tourist visa application, with the requested validity being from 3 to 16 August.  Now she's considering entering the evening before, so I would like to ask the following:  The Train she wants to take arrives at Vyborg (first Russian station) on 2 August at 22:22, then St Petersburg at 23:27. The Russian border guards board the train at Vyborg and do the checks while the Train is travelling between the stations, so sometime between 22:30-23:00  If the visa validity starts on 3 August, and she is checked at 22:30-23:00 the evening before, what would happen? Are they very strict about the starting date if it's within 1-1.5 hours, and how bad would the consequences be?  Although they do the check while travelling between Vyborg and St Petersburg, could they simply wait until arrival in St Petersburg, then hold her in custody for 30 minutes and then stamp her in? How to prove the convergence of $\sum_{n\geq 0}\frac{n!^d}{(dn)!}$ for $d\geq 2$? How can we find the general formula about the convergence of the serie $\sum_{n=0}^\infty \frac{(n!)^d}{(dn)!}$ for all $d\geq2$ ?  I tried using the d'Alembert Criteria but it doesn't simplify itself enough to prove the convergence. Is there a better name for this than "emphatic and"? In semi-poetic writing, I have had occasion to deviate from the standard prose list practice (interpose commas or semicolons between items, with an "and" preceding the final item), by utilizing a second or third and to separate three or four items.  That is,       Bob likes beer, wine and liquor.   The variant would be:     Bob likes beer and wine and liquor.   Now, the usage is obviously nonstandard and should be avoided in formal writing, but for those instances where poetic variation may be justified.    What is it called?  "Emphatic And" is the best I can coin on my own, but I wonder if there is a more established name for this variation. I saw this today, I checked in Mathematica and the integral comes out to $\pi$, but I have no idea how to solve it.     FREE Wi-Fi: The Wi-Fi password is the first $10$ digits of the answer.   $$\int_{-2}^2\left(x^3\cos\frac x2+\frac12\right)\sqrt{4-x^2}\ dx$$ Growing a PostGIS geometry by a percentage Best way to capture historical changes between levels in a dimensional hierarchy What is the cleanest way to capture changes between levels in a dimensional hierarchy?  I have the dimensional hierarchy [Area] > [Region] > [Location], where Area is the parent to Region and Region is the parent to Location. Location is lowest level of the hierarchy, and is associated with the fact table.  The business rules are: Locations are able to change the Region they are assigned to based on business need. Furthermore, Regions are able to change the Area they are assigned to.  We want to capture those changes so that when we do historical analysis, we can compare business metrics before and after a Location changed its Region, and a before and after a Region changed its Area.  What is the best way to do this?  The four ways that I have come up with all seem to have major drawbacks:   Using a bridge table between hierarchy levels requires that you use time bounds (effective start/end dates) to correctly identify which parent a child belongs to as you walk up the hierarchy. That makes queries prone to error, especially with hierarchies with many levels. Versioning a child record whenever its relationship to its parent changes (e.g., versioning Region A when it moves from Area A to Area B) and then cascading that change all the way down the hierarchy (e.g., creating new versions of Locations tied to Region A so that they are tied to the new Region A). Updating the child record's reference to the parent record, making you use time bounds to reassemble the correct history (prone to error). Always use time bounds when querying up the hierarchy to make sure Location A is associated with the correct Region (likewise, Region A is associated with the correct Area) for the moment of the fact being analyzed.   None of these seems clean to me.  Is there a better way?  Thanks a lot Subsurf Modifier artifacts So I was messing with Subsurf modifier to create a certain sword and then some weird artifacts began to appear (cape-like). I've tried adjusting the Crease, but couldn't achive what I wanted. Basicly, what I whant is the as on the screens, but wo any artifacts :)   Also, here's the .blend file, cause I assume I didn't make myselt 100% clear. OpenGL Texture Coordinates in Pixel Space Find the area of largest rectangle that can be inscribed in an ellipse The actual problem reads:      Find the area of the largest rectangle that can be inscribed in the ellipse    $$\frac{x^2}{a^2} + \frac{y^2}{b^2} = 1.$$   I got as far as coming up with the equation for the area to be $A=4xy$ but then when trying to find the derivative I don't think I'm doing it right. How do we define capillary number in 2D (two dimensions) In 3D the capillary number $Ca$ is defined as: $$Ca=\frac{\nu \rho U}{\gamma}$$ where $\nu$ is the kinematic viscosity ($m^2/s$), $U$ is the velocity ($m/s$)and $\gamma$ is the interfacial tension ($N/m$) and $\rho$ is the density in $kg/m^3$ . However in 2D I will have $\rho$ in units of $kg/m^2$ (2D simulation), so how to find capillary number? A strict equality operator will tell you if two object types are equal. However, is there a way to tell if two objects are equal, much like the hash code value in Java?  Stack Overflow question  is similar to this question, but requires a more academic answer. The scenario above demonstrates why it would be necessary to have one, and I'm wondering if there is any equivalent solution. Trackpad not working after update to Ubuntu 14.10 on Dell Inspiron 15R When I updated from 14.04 to 14.10 I noticed my track-pad cursor and left and right mouse clickers were not working. I have tried looking this issue up and can not find any solutions anywhere. If anyone could help me that would be amazing, I am using a wired mouse to my USB port for a temporary fix. I have a Dell Inspiron 15R. Find $P(n+1)$ for a polynomial P Fix a nonnegative integer $n$. Let $P(x)$ be a polynomial of degree $n$ (over the real numbers) such that for all $k\in\left\{0,1,\ldots,n\right\}$, we have $P(k)=\dfrac{k}{k+1}$. Find $P(n+1)$.   My attempt:  I consider a new polynomial $Q(x)=(x+1)P(x)-x$. This $Q$ is a polynomial of degree $\leq n+1$ satisfying: $Q(k)=0\quad\forall k\in\{0,1,2,\ldots,n\}$. Therefore $Q(x)=\lambda x(x-1)\cdots(x-n)$ for a certain real $\lambda$. Hence, $Q(-1)=\lambda \cdot (-1)^{n+1}(n+1)!$, but also $Q(-1)=(-1+1)P(-1)+1=1$. Comparing these, we get $\lambda \cdot (-1)^{n+1} (n+1)! = 1$, thus $\lambda=\dfrac{(-1)^{n+1}}{(n+1)!}$. Since $Q(n+1)=\lambda(n+1)!$ then $Q(n+1)=(-1)^{n+1} $, and from $P(x) = \dfrac{Q(x)+x}{x+1}$ we deduce: $$P(n+1)=\dfrac{(-1)^{n+1}+n+1}{n+2}.$$ I doubted that the answer were $P(n+1)=\frac{n+1}{n+2}$ but the term $(-1)^{n+1}$ wasn’t expected. Is there any mistake here? Does someone have an alternative proof? I know this is a really basic question, but I've just started with some basic C++ programming after coding a few projects with high-level languages.   Basically I have three questions:   Why use pointers over normal variables? When and where should I use pointers? How do you use pointers with arrays? Who is the authority -- scientists, or linguists -- on the definitions of everyday words referring to types of animals? find examples of two series $\sum a_n$ and $\sum b_n$ both of which diverge but for which $\sum \min(a_n, b_n)$ converges Find examples of two series $\sum a_n$ and $\sum b_n$ both of which diverge but for which $\sum \min(a_n, b_n)$ converges. To make it more challenging, produce examples where $a_n$ and $b_n$ are positive and decreasing.  Edit: This problem is taken verbatim from Exercise 2.7.11 on page 68 of Abbott's Understanding analysis. Scale settings for exporting to STL (for 3d printing) I've set my Units (in scene properties) to Metric, and the Scene Scale to 0.01 hoping to get the Blender dimensions it mm's. While the (normal) scale is 1 for x,y,z, the standard cube has the dimensions 2x2x2 cm. When I export this to an STL and open it in a slicing program (Netfabb, Slic3r or Cura) they all give the dimensions: 2x2x2 mm. While exporting, the scale is 1.  What am I doing wrong? I hope you can help me.  Thanks! Is LED properly implemented in the constant current circuit? Get string inside parentheses, removing parentheses, with regex