I checked several questions at this community about the issue but did not works out as a solution.  I am trying to run the LaTex code on my machine, but it stopped working for this file.   I have tried to reopen an old file that I have implemented before at my machine and it works fine without any error. Can anyone give a hint what shall I do to make it compilable?      Error screenshoted below.
This is my first time using a LaTeX editor.   I installed  allowing it to use the default directory on the C drive.  Software Versions   Windows: 7 Ultimate 64-bit  Texmaker 3.4.1 for Windows   I then did A Local guide for using Texmaker (There use to be a link to this but it is now dead)  Basically create a simple Hello World document and save it.  When I went to process the file   Tools -&gt; PDFLaTeX     I received    Error: Log file not found!   What I checked  I checked the configuration (Options -> configure Texmaker) and found no option for log files.  I checked for a log file under the C:\Program Files (x86)\Texmaker and found none.  I checked for a log path in the Windows registry using regedit and found none.  I checked the Texmaker issues and found  but it does not help.  Any ideas?  After reading answer  I installed MiKTeX as an administrator (didn't work as user) and chose the default options. After MiKTeX installed I was able to create a PDF file using Texmaker.   Also, correctly setting the PDF viewer options   Options -&gt; Configure Texmaker -&gt; Commands -&gt; PDF Viewer Built-in Viewer and Embed   I was able to preview the pdf in Texmaker   View -&gt; PDF Viewer   What I learned   is a LaTeX editor which generates a file containing LaTeX markup.     is a program that converts the LaTeX markup into an output format such as PDF.
How can a photon have no mass and still travel at the speed of light? The  states that:      The scores are created by comparing the word in the list in step 2* with all the 3-letter words. By using the scoring matrix (substitution matrix) to score the comparison of each residue pair, there are 203 possible match scores for a 3-letter word. For example, the score obtained by comparing PQG with PEG and PQA is 15 and 12, respectively with the BLOSUM62 weighting scheme.   I do not understand how they got a score of 15 for PQG v. PEG. What is a scoring matrix, how is it computed, and how is it used?      Step 2 on that page is Make a k-letter word list of the query sequence: “Take k=3 for example, we list the words of length 3 in the query protein sequence (k is usually 11 for a DNA sequence) sequentially, until the last letter of the query sequence is included”. "Mixed declaration and code" warning, is it worth addressing? How to prove $ \prod_{d|n} d= n^{\frac{\tau (n)}{2}}$ Basic desktop actions are not available on Ubuntu 20.04 In Ubuntu 20.04, on the desktop, there is a number of actions I wish I could do, such as, by order of importance :  use keyboard shortcuts such as select all, copy / paste. use drag &amp; drop with icons deactivate the &quot;mouse over&quot; highlight, and restrict the clicking area to only the icon, not the surrounding square  To put it simply, I'd like to have the exact same features as offered by the desktop of Ubuntu 18.04 (probably related to a specific version of GNOME, and not Ubuntu itself). Am I missing something obvious here? I actually see no reason why those actions are removed or deactivated on the desktop, since they all work in any Nautilus window. How can I change the registered name in Windows 7 to my own? How to implement dual-classing in a non-levelled RPG game? I'm working on an alternate ruleset for a tabletop pen-and-paper RPG (like D&amp;D). Recently I've been toying the idea of abolishing a level system. However, I don't want to remove the ability for a player to multi-class. Are there any games which don't have a levelling system, yet allow multi-classing? How do they do it successfully? Why are there scenes that will not render on GPU but will render fine on CPU? I've already tried GPU Rendering and it seem to be twice as fast as the CPU. However I have some situation where tried to render on the GPU, but it doesn't do anything. When I switch to CPU it renders.  I have some fur texture/materials using particle systems. I wonder if that causes the GPU not to render, I'm not really sure. In The Force Awakens, we see Rey pouring some flour-like polystarch rations into water so that the flour amazingly transforms into something that looks like bread. What are these rations? Is there any documentation of the fictional chemistry and biology that makes the starch rations behave as they do? How do I get the first element from an IEnumerable in .net? I often want to grab the first element of an IEnumerable&lt;T&gt; in .net, and I haven't found a nice way to do it.  The best I've come up with is:  foreach(Elem e in enumerable) {   // do something with e   break; }   Yuck!  So, is there a nice way to do this? Alternative to Photoshop or Paint.NET How to use iSight webcam without activating the green light? Recently a the Dutch government advised to put a tape on your webcam to prevent hackers from taking pictures and video using your device ().  The build in iSight camera in Apple laptops have a green light next to the camera, this light turns green when you use the camera.  Is it possible to use the camera without the activation of the green light? Personally I think the green light turns on when the sensor requires power and this is hardwired in the hardware. Am I wrong?  I have found similar questions on stackexchange, but I found non that answer this specific question. How to bottle your own homemade salad dressing Not every open set in $\mathbb{R}^n$, for $n\geq2$, is a disjoint union of countable open balls. I know that every open set in $\mathbb{R}$ can be decomposed as the union of countably many disjoint open intervals and I'm trying to show that this property no longer holds in higher dimensions. For this I'm trying to show that there is no countable, pairwise disjoint open balls whose union is the open square $(0, 1)^2 ⊂ \mathbb{R}^2$. I know that it is because of the corners, but I don't know how to write this in mathematical terms. Thanks for any help. How does one attack a two-time pad (i.e. one time pad with key reuse)? Problem numbering environment USB sticks and multiple partitions Not every boolean function is constructed from $\wedge$ (and) and $\vee$ (or) Words for "a bit sad" and "a bit happy"? I got this problem from my teacher as a optional challenge. I am open about this being a given problem, however it is not homework. The problem is stated as follows. Assume we have an infinite tetration as follows $$x^{x^{x^{.^{.^.}}}} \, = \, a$$ With a given $a$ find $x$. The next part of the problem was to discuss the convergence radius of a. If a is too big or too small the tetration does not converge. Below is my humble stab at the problem.  My friend said you would have to treat the tetration as a infinite series, and therefore could not perform algebraic manipulations on it before it is know whether it converges or diverges. However my attempt is to first do some algebraic steps, then discuss the convergence radius. I) Initial discussion At the start it is obvious that the tetration converges when $a=1$ (just set $x=1$) Now after some computer hardwork it seems that the tetration fails to converge when a is roughly larger than 3. II) Algebraic manipulation $$ x^{x^{x^{.^{.^.}}}} \, = \, a$$ This is the same as $$ x^a \, = \, a$$ $$ \log_a(x^a) \, = \, \log_a(a)$$ $$ \log_a(x) \, = \, \frac{1}{a}$$ $$ x \, = \, a^{\frac{1}{a}}$$ Now, if we let $a=2$ then $x = \sqrt{2}$. After some more computational work, this seems to be correct, which makes me believe this formula is correct. III) Discsussion about convergence By looking at the derivative of $ \displaystyle \large a^{\frac{1}{a}} $ we see that the maxima occurs when $a=e$, which also seems to correspond to the inital computational work. Now I think, that the minima of $\displaystyle \large a^{1/a}$ is zero by looking at its graph, studying its derivative and the endpoints. So that my &quot;guess&quot; or work shows that it converges when $$ a \in [0 \, , \,  1/e] $$ VI) My questions Can my algebraic manipulations be justified? They seem rather sketchy taking the a`th logarithm and so on . (Although they seem to &quot;magically&quot; give out the right answer) By looking at Wikipedia it seems that the tetration converge when $$ a \in \left[ 1/e \, , \, e \right] $$ This is almost what I have, why is my lower bound wrong? How can  I find the correct lower bound?