Gradient of $x^{T}Ax$
How to take the gradient of the quadratic form?
All I want to see are the specs Is there a way to see the processor and speed of a Cisco UCS B230 Blade Server without the enclosure that runs it? The enclosure that we have does not power on and all I need is to see what cpu and processor speed is in it. I'm having trouble understanding the wording of one of my homework questions. Since this question appears early in the chapter, I have a feeling that I'm misinterpreting it.  Give a finite automaton that that accepts the following language: The language over $\{a, b\}$ of any even number of $a$'s and any odd number of $b$'s.   I'm having trouble with the usage of "and". Is it asking for an FA that accepts any string that is either an even number of $a$'s or an odd number of $b$'s, e.g. $aa$, $bbb$, $aaaa$, etc, but not accept strings like $aabbb$, $abbab$.   Or, is it asking for an FA that accepts any string that contains an even number of $a$'s or an odd number of $b$'s, e.g. $aabbb$, $ababb$, etc.   The first case is relatively simple, but I've been struggling with the second. I haven't even managed to convince myself that it is a regular language (because I haven't been able to come up with a regular expression that matches it).   My questions: Which interpretation seems most likely. Is the second case a regular language, if so, give a regular expression that recognizes it. How to favorite a question from Android app? Why do different wavelength get impeded more or less when in different materials? Moving with the same speed, but a longer physical distance would imply that the fields oscillate less times in the material, but I don't know why a difference in the number of oscillations would impede the wave- I don't even know why things slow down in general. Why some electromagnetic wave would slow down just because it's entering other electromagnetic fields... It would seem to me that the only factor would be time taken to physically move some electron or something in the direction of the fields... But that seems to simple of an explanation to me. when calling SCP in PuTTY on my Win7 box, it doesn't let me use C:/, but I also have no idea where on my local machine it will look for files by default. None of program directory or user directory worked. For example, I saved file.txt next to PuTTY.exe, and also in C:\Users\Me but calling SCP file.txt file.txt in PuTTY failed both times with      cp: cannot stat 'file.txt'   So, how do I transfer a file to my server using PuTTY?  EDIT: Also, calling SCP file.txt myserver:file.txt gives a similar error: file.txt: No such file or directory I'm not able to get access to $wpdb How can I disable a USB port in Windows XP to make it available only for smart phone battery charging?   I don’t want the users to be able to see the USB drive in My Computer, and the USB device should stay disabled in Device Manager.   Is there any way to accomplish this? Stack Overflow has left! A lot of my scripts stopped working after installing Ubuntu 15.10 and I have trouble remembering this new name as I was used to ethx and wlanx for years. Is there a reason for this change? Do I have to get used to this or can I just rename it and go back to good old eth0?  $ ifconfig  enp0s25   Link encap:Ethernet  HWaddr 77:5a:5e:a6:86:d5         inet addr:192.168.31.239  Bcast:192.168.31.255  Mask:255.255.255.0       inet6 addr: fe80::725a:b6ff:fea6:86d7/64 Scope:Link       UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1       RX packets:4833 errors:1332 dropped:0 overruns:0 frame:666       TX packets:5589 errors:0 dropped:0 overruns:0 carrier:0       collisions:0 txqueuelen:1000        RX bytes:3266446 (3.2 MB)  TX bytes:1046654 (1.0 MB)       Interrupt:20 Memory:d3500000-d3520000 Replace a xtick by a letter in Tikz How to show $f'(0)$ exist and is equal to $1$? How do I root my Nexus 7? I am wanting to gain root privileges on my Google Nexus 7 tablet, running Android 4.1-4.2.1. How can I do this? Plotting a Continuous signal For $x,y\in\mathbb{N}$ how many ordered pairs $\left(x,y\right)$ satisfy   $\dfrac{1}{x}+\dfrac{1}{y}=\dfrac{1}{pq}$ where $p,q$ are distinct primes? So, I'm working creating a lamp... yes, newbie here.  After modeling for a bit, I noticed that my point of origin was no longer the center of my object:    How to I reset an object origin point to the center of it's geometry? Markdown in chat fails for multi-line messages If Z is a square integrable random variable such that $E[Z]&gt;0$, then prove that  $$P(Z\geq k) \geq \frac{(E(Z)-k)^2}{E(Z^2)} \forall k \in [0,E(Z)]. $$  This is a homework question and I don't even understand why the inequality is reversed comparing to Markov/Chebychev inequality. Should Cauchy-Schwartz inequality be used? If yes, then how to begin? Thanks a ton! Embedding a link (or other html) in a JSF message How to revert uncommitted changes including files and folders? How to open Nautilus at current command line directory? I was wondering if anybody knew a command that would allow me to open a Nautilus (if that's the right name for the Ubuntu graphic/window explorer) window from the command line at the current directory that the user is at.  So, if I open a command line, and type:  cd /home/myUser/some/long/path/to/a/directory   Then, I'd like to be able to issue some command:  nautilus open-sesame   And have a graphic window opened to /home/myUser/some/long/path/to/a/directory. Is this even possible?