2.7 hidden object problems to 2.8 in 2.7 my file the items were saved hidden 2.8 the same items are not unable to be unhidden. it is a lot of work and put in this and if you tell me how to fix and/or update to repair this problem would be nice
Can't unhide grayed out objects After some searching on stack / google I decided to ask this here, this is the second time I'm facing this issue this time with blender 2.8, previously with 2.7 and without a clue to how I got here.  Some of my objects appear hidden(10/12), and I can't seem to find a way to unhide them.  Solutions to the most common rookie mistakes seems to be   In local-view solved by pressing numpad / hidden by pressing H or Shift + H, unhiding with Alt + H   I'm not in local view, I can toggle visibility for 2/12 objects with Shift + H &amp; Alt + H, but the rest stays gray in the collection.  Last time I solved this by exporting the whole model as STL and importing it back again, I then had to re-group all the pieces but there must be a more simple solution.  Here's the .blend if someone wants to have a go at it:
Proving $\sum_{k=0}^n\binom{2n}{2k} = 2^{2n-1}$ I'm undergraduate student of mathematics.  I need to prove: $$\sum_{k=0}^{n} \binom{2n}{2k}= 2^{2n-1}$$ Can you please help me How do I set the default program? \end{abstract} conflicts with arabtext package I am using elsarticle  Everything was find before I used \usepackage{arabtext}.   When I compiled to PDF, I got the following error message.    And if I type "s", everything became fine again but I don't want to type an "s" every time I compile PDF preview.   Please anyone advise.  Thank you very much in advance for your help.  Here is the code  \documentclass[12pt, authoryear]{elsarticle}    % use "amsart" instead of "article" for AMSLaTeX format \usepackage[colorlinks=true,linkcolor=black, citecolor=blue, urlcolor=blue]{hyperref} \usepackage{geometry}                       % See geometry.pdf to learn the layout options. There are lots. \geometry{a4paper}                          % ... or a4paper or a5paper or ...  %\geometry{landscape}                       % Activate for rotated page geometry %\usepackage[parfill]{parskip}          % Activate to begin paragraphs with an empty line rather than an indent \usepackage{graphicx}               % Use pdf, png, jpg, or epsÂ§ with pdflatex; use eps in DVI mode                             % TeX will automatically convert eps --&gt; pdf in pdflatex         \usepackage{amssymb}  \usepackage{amsmath} \usepackage{tipa} \usepackage{arabtex} %SetFonts  %SetFonts   \title{Translating from English to Bahasa Indonesia: Which procedures should be taught to EFL students preparing to be a translator?} \author[mkl]{Mohammad Kholid}  \author[fai]{Faisal Mustafa\corref{cor1}} \ead{faisal.mustafa@unsyiah.ac.id}  \cortext[cor1]{Corresponding author}  \address[mkl]{Syiah Kuala University, Banda Aceh, Indonesia} \address[fai]{Syiah Kuala University, Banda Aceh, Indonesia} \date{}                         % Activate to display a given date or no date  \begin{document} %\section{} %\subsection{}  \begin{frontmatter}  \begin{abstract}   Abstract content is here.  \end{abstract}  \begin{keyword}  translation procedures \sep English to Bahasa Indonesia \sep teaching translation \end{keyword} \end{frontmatter} How to tell a lambda function to capture a copy instead of a reference in C#? I've been learning C#, and I'm trying to understand lambdas.  In this sample below, it prints out 10 ten times.  class Program {     delegate void Action();     static void Main(string[] args)     {         List&lt;Action&gt; actions = new List&lt;Action&gt;();          for (int i = 0; i &lt; 10; ++i )             actions.Add(()=&gt;Console.WriteLine(i));          foreach (Action a in actions)             a();     } }   Obviously, the generated class behind the lambda is storing a reference or pointer to the int i variable, and is assigning a new value to the same reference every time the loop iterates.  Is there a way to force the lamda to grab a copy instead, like the C++0x syntax  [&amp;](){ ... } // Capture by reference   vs.  [=](){ ... } // Capture copies What affects field upgrades in BF4? I'm trying to find the roots of $x^4+1$. I've already found in this site solutions for polynomials like this $x^n+a$, where $a$ is a negative term. I don't remember how to solve an equation when $a$ is a positive term as the equation above.  Thanks All of my Firefox extensions were spontaneously and simultaneously disabled (converted to Legacy status) a few moments ago.  How can I re-enable them? Firefox 66.0.3 (64-bit) Column vs Field: have I been using these terms incorrectly? I feel kind of embarrassed here, I've always used the terms "column" and "field" completely interchangeably, which recently caused some confusion in a technical discussion.   I was told, though, that this wasn't correct, that it should be (translating each term into spreadsheet terminology, ignoring data types and all the other stuff that make databases useful):   Database Column: like a spreadsheet column  Database Record: like a spreadsheet row Database Field: like a spreadsheet "cell" (a specific column of a specific row)   Is this right? I could have sworn that column and field are used more interchangeably than that. I certainly have been.  So we don't add fields to a table, we add columns to a table, and fields are only relevant when talking about data within a record?  Other thoughts on column vs field?  Edit: to clarify, the current context is MS SQL Server. My background before SQL server was MS Access, which might influence my use of these terms. I have a Non Root User abc and want to give the user sudo rights only to restart, start or stop - mysqld service. i.e sudo service mysqld restart. How can I do it so?     I would like to do the same to usergroup too!! Really stuck with this, \begin{cases}  2tx'(t)-1=x^2t \\  x(t=1)=1 \\  \end{cases} I don't understand the variables. What does it mean that $x$ differentiated have $t$ as a function value, like this: $x'(t)$? Don't get it :( Why don't Jedi (or Sith) use the Force to snap their foes' necks? I understand that the Jedi use the Force for self defence, but still, couldn't they just use the Force to snap their foes' necks and be done with it? Like when Jaina Solo was hunting down Darth Caedus. Or even when Caedus was duelling Grand Master Skywalker. If he just used the Force to snap Skywalker's neck (like he did to poor Lieutenant Tebut), it will all be over very fast.  Is there a canon reason why Jedi and Sith don't use their powers to directly harm their opponents? Does electricity flow on the surface of a wire or in the interior? Windows 10 - Users already logged in at boot Short story where the Earth has been kept inside a force field for millennia I bought a used iPhone 4.  The previous owner re-set the phone, but did not remove the device from their iCloud.  It is asking me for their iCloud information when I try to set-up the phone.  I don't have contact with the previous owner anymore.  Is there a way to remove the device from their iCloud so I can use a new one? How do I move the "Show Applications" icon in Ubuntu Dock? Ubuntu 17.10 introduces the GNOME Shell with the  (based on  GNOME Shell extension) and it allows you to put the Dock on the bottom of the desktop:    However, there is no easy way to move the Show Applications icon (shown on the right) to the left of the Dock. There is no such setting in GNOME Control Center. There is already a  filed, but does anybody know any workaround until it gets fixed by Ubuntu Dock developers? Can a Byte[] Array be written to a file in C#? Inconsistent line spacing What is a good book to learn number theory? Fill the area determined by two pgfplots graphs I need to fill the region determined by two (Gaussian) curves and the right red line (the region is brushed in green in the figure below). I also wonder what is the best way to draw vertical line which goes through the intersection of both graphs (the left red line on the figure).  Any pointers would be greatly appreciated.    My initial attemt is pasted below.  \documentclass{standalone} \usepackage{pgfplots}  \begin{document}  \pgfmathdeclarefunction{dnorm}{2}{%   \pgfmathparse{1/(#2*sqrt(2*pi))*exp(-((x-#1)^2)/(2*#2^2))}% }  \begin{tikzpicture} \begin{axis}[domain=0:12, samples=100, height=5cm, width=10cm] % Fill aread under the curves \addplot [fill=red!20, draw=none, domain=0:6] {dnorm(6.5,1.5)} \closedcycle; \addplot [fill=blue!20, draw=none, domain=6:10] {dnorm(4,1)} \closedcycle; % Draw curves \addplot [thick] {dnorm(4,1)}; \addplot [thick] {dnorm(6.5,1.5)}; \end{axis} \end{tikzpicture}  \end{document}   My solution  A picture is worth a thousand words. Code is pasted below.   \documentclass{article} \usepackage{tkz-fct} \usetikzlibrary{intersections}  \begin{document}  \tikzset{    name plot/.style={every path/.style={name path global=#1}} }  % Extract coordinates for point X \makeatletter \newcommand{\gettikzxy}[3]{%   \tikz@scan@one@point\pgfutil@firstofone#1\relax   \edef#2{\the\pgf@x}%   \edef#3{\the\pgf@y}% } \makeatother  % Dimlines \def\Dimline[#1][#2][#3][#4]{ \begin{scope}[thin, &gt;=stealth'] % redefine as flechas \draw let \p1=#1, \p2=#2, \n0={veclen(\x2-\x1,\y2-\y1)} in [|&lt;-&gt;|, decoration={markings,mark=at position .5 with {\node[#3] at (0,0) {#4};}, }, postaction=decorate] #1 -- #2 ; \end{scope} }  \begin{tikzpicture}[scale=1,font=\small] \tkzInit[xmin=0,xmax=12,ymin=0,ymax=.3,ystep=.05] % Draw coordinates \draw[&gt;=stealth', &lt;-&gt;] (0,6) node[above] {$y$} -- (0,0) --  (12.5,0) node[right] {$x$}; % Draw functions and areas \tkzFct[name plot=A,thick,color=red,domain=0:12]{1/(1.5*sqrt(2*pi))*exp(-((x-4.5)**2)/(2*1.5**1))} \tkzDrawArea[opacity=.3,color=blue,domain = 7:12] \tkzFct[name plot=B,thick,color=blue,domain=0:12]{1/(2*sqrt(2*pi))*exp(-((x-7)**2)/(2*2**1))} \tkzDrawArea[opacity=.3,color=red,domain=0:7] \tkzDrawAreafg[between=b and a,opacity=.3,color=green,domain = 0:7] % Intersection between curves \path [name intersections={of=A and B,by=C}]; % Extract coordinates of C \gettikzxy{(C)}{\cx}{\cy} % Vertical lines \draw [thick,dashed, black] (\cx,0) -- (\cx,5.5) node [above] {$x_{0}$}; \draw [thick,dashed, black] (7,0) -- (7,5.5) node [above] {$\hat{x}$}; % Define regions \Dimline[($(0,0)+(0,-.6)$)][($(7,0)+(0,-.6)$)][above,black][$\mathcal{R}_{1}$]; \Dimline[($(7,0)+(0,-.6)$)][($(12,0)+(0,-.6)$)][above, black][$\mathcal{R}_{2}$]; \end{tikzpicture}  \end{document}