I cannot find my bluetooth devices (headphones or mouse) when scanning with my laptop after installing Ubuntu. Can't find using terminal, [bluetoothctl] or with Bluetooth Manager. I used these exact devices with this laptop when it was running Windows 10, but after installing Ubuntu, it will no longer detect these bluetooth devices. Below are outputs to commands requested by others who had a similar problem. $ lsusb; dmesg | egrep -i 'blue|firm' Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 001 Device 003: ID 04f3:21d5 Elan Microelectronics Corp. Touchscreen Bus 001 Device 002: ID 0a5c:6410 Broadcom Corp. BCM20703A1 Bluetooth 4.1 + LE Bus 001 Device 004: ID 1bcf:2b95 Sunplus Innovation Technology Inc. Integrated_Webcam_HD Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub [    0.135795] Spectre V2 : Enabling Restricted Speculation for firmware calls [    0.205620] ACPI: [Firmware Bug]: BIOS _OSI(Linux) query ignored [    2.541258] Bluetooth: Core ver 2.22 [    2.541273] Bluetooth: HCI device and connection manager initialized [    2.541275] Bluetooth: HCI socket layer initialized [    2.541278] Bluetooth: L2CAP socket layer initialized [    2.541280] Bluetooth: SCO socket layer initialized [    2.619994] [drm] Finished loading DMC firmware i915/skl_dmc_ver1_27.bin (v1.27) [    2.669873] Bluetooth: hci0: BCM: chip id 102 [    2.670867] Bluetooth: hci0: BCM: features 0x2f [    2.686877] Bluetooth: hci0: akilakas-XPS [    2.687870] Bluetooth: hci0: BCM (001.001.005) build 0000 [    2.688016] bluetooth hci0: Direct firmware load for brcm/BCM-0a5c-6410.hcd failed with error -2 [    2.688017] Bluetooth: hci0: BCM: Patch brcm/BCM-0a5c-6410.hcd not found [    2.720000] brcmfmac 0000:02:00.0: Direct firmware load for brcm/brcmfmac43602-pcie.Dell Inc.-XPS 15 9550.txt failed with error -2 [    2.720023] brcmfmac 0000:02:00.0: Direct firmware load for brcm/brcmfmac43602-pcie.txt failed with error -2 [    3.226327] brcmfmac: brcmf_c_preinit_dcmds: Firmware: BCM43602/1 wl0: Nov 10 2015 06:38:10 version 7.35.177.61 (r598657) FWID 01-ea662a8c [    3.453028] Bluetooth: BNEP (Ethernet Emulation) ver 1.3 [    3.453030] Bluetooth: BNEP filters: protocol multicast [    3.453033] Bluetooth: BNEP socket layer initialized [    4.414972] Bluetooth: RFCOMM TTY layer initialized [    4.414978] Bluetooth: RFCOMM socket layer initialized [    4.414982] Bluetooth: RFCOMM ver 1.11
Bluetooth is on but can't find or be found by any other devices.  Output of sudo service bluetooth status:  ● bluetooth.service - Bluetooth service    Loaded: loaded (/lib/systemd/system/bluetooth.service; enabled; vendor preset: enabled)    Active: active (running) since ხუთ 2015-06-04 22:33:18 GET; 13min ago  Main PID: 26678 (bluetoothd)    CGroup: /system.slice/bluetooth.service            └─26678 /usr/sbin/bluetoothd -n  ივნ 04 22:39:14 Rangoo bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/HFPAG ივნ 04 22:39:14 Rangoo bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/HFPHS ივნ 04 22:39:14 Rangoo bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/A2DPSource ივნ 04 22:39:14 Rangoo bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/A2DPSink ივნ 04 22:39:14 Rangoo bluetoothd[26678]: bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/HFPAG ივნ 04 22:39:14 Rangoo bluetoothd[26678]: bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/HFPHS ივნ 04 22:39:14 Rangoo bluetoothd[26678]: bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/A2DPSource ივნ 04 22:39:14 Rangoo bluetoothd[26678]: bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/A2DPSink ივნ 04 22:39:14 Rangoo bluetoothd[26678]: Adapter /org/bluez/26678/hci0 has been enabled ივნ 04 22:39:14 Rangoo bluetoothd[26678]: bluetoothd[26678]: Adapter /org/bluez/26678/hci0 has been enabled   Output of lsusb:  Bus 003 Device 005: ID 0a5c:21d7 Broadcom Corp. BCM43142 Bluetooth 4.0   How can I fix it?
How do I programmatically force an onchange event on an input? How do I programmatically force an onchange event on an input?  I've tried something like this:  var code = ele.getAttribute('onchange'); eval(code);   But my end goal is to fire any listener functions, and that doesn't seem to work.  Neither does just updating the 'value' attribute. Solving the recurrence $T(n) = \sqrt n T(\sqrt{n}) + \sqrt{n}$ A former student of mine was TA-ing an algorithms class last quarter and asked students to solve this famous recurrence relation:  $$T(n) = \sqrt n T(\sqrt{n}) + n$$  There are  and this question has already been asked here.  I was talking to my student about this problem and mentioned that it's quite hard to solve and is pretty dependent on the particular choices being made. As an example, I suggested this variant of a recurrence relation that was less simple to solve:  $$T(n) = \sqrt n T(\sqrt{n}) + \sqrt{n}$$  The TA and I tried solving this recurrence for about an hour and a half without making any progress. Here are a few things we tried:   My approach to solving the initial recurrence relation was to draw out a recursion tree and notice that each level of the tree contributes $n$ to the total and that there are $O(\log \log n)$ layers, so the recurrence solves to $O(n \log \log n)$. When I tried doing this here, I noticed that the work per layer was no longer constant; instead, the top layer sums to $\sqrt{n}$, the second layer to $n^{3/4}$, the third to $n^{7/8}$, etc. We got stuck working with the summation $n^{1/2} + n^{3/4} + n^{7/8} + ...$. We tried using the iteration method to unroll the recurrence. With the original recurrence relation, this works out nicely; here, we got stuck at the same summation given above.   I'm completely stuck trying to figure out how to solve this recurrence relation. There's nothing riding on it per se - I don't need to solve it for any particular reason - but the fact that we arrived at it by a straightforward modification of a common algorithms problem set question makes it all the more enticing.  Any idea how to solve this recurrence?  Thanks! Why there is a delay between when a key is pressed and when it is accepted? Repeat each line multiple times Would like to have each line in a file repeated a fixed number of times.  e.g. have each line repeated four times:  a b c   becomes:  a a a a b b b b c c c c   I've done some searching, and there are a lot of questions and answers along the lines of doing the reverse, e.g. merging duplicate lines into single lines, and maybe a few about doubling lines by printing them again.  It would be easy to do this in C, but I wish I knew more about the native commands so I wouldn't have to resort to these kinds of one-off throw-aways all the time. Infinitely number of primes in the form $4n+1$ proof Question: Are there infinitely many primes of the form $4n+3$ and $4n+1$?  My attempt: Suppose the contrary that there exist finitely many primes of the form $4n+3$, say $k+1$ of them: $3,p_1,p_2,....,p_k$  Consider $N = 4p_1p_2p_3...p_k+3$, $N$ cannot be a prime of this form. So suppose that $N$=$q_1...q_r$, where $q_i∈P$  Claim: At least one of the $q_i$'s is of the form $4n+3$:  Proof for my claim: $N$ is odd $\Rightarrow q_1,...,q_r$ are odd $\Rightarrow q_i \equiv 1\ (\text{mod }4)$ or $q_i ≡ 3\ (\text{mod }4)$  If all $q_1,...q_r$ are of the form $4n+1$, then $(4n+1)(4m+1)=16nm+4n+4m+1 = 4(\cdots) +1$  Therefore, $N=q_1...q_r = 4m+1$. But $N=4p_1..p_k+3$, i.e. $N≡3\ (\text{mod }4)$, $N$ is congruent to $1\ \text{mod }4$ which is a contradiction.  Therefore, at least one of $q_i \equiv 3\ (\text{mod }4)$. Suppose $q_j\equiv 3\ (\text{mod }4)$  $\Rightarrow$ $q_j=p_i$ for some $1\leq i \leq k$ or $q_j =3$  If $q_j=p_i≠3$ then $q_j$ | $N = 4p_1...p_k + 3 \Rightarrow q_j=3$ Contradiction!  If $q_j=3$ ($\neq p_i$, $1\leq i \leq k$) then $q_j | N = 4 p_1...p_k + 3 \Rightarrow q_j=p_t$ for some $1 \leq i \leq k$ Contradiction!  In fact, there must be also infinitely many primes of the form $4n+1$ (according to my search), but the above method does not work for its proof. I could not understand why it does not work. Could you please show me?  Regards How to install wps office via terminal? It's pretty complicated and sometimes the system freezes when I try to download and install wps office. I think it is much more convenient to use the terminal. But I never used installed WPS Office from the command line. That would be great if I could update it using software manager or terminal. Third party deb files are from separate locations. I specifically want to know about WPS Why the CMB has not been dispersed so far? Imagine you have a box of black body radiation. What happens if you open the box for a long time? It becomes dispersed and no radiation remains in the box.   Now, apply this example to the Cosmic Microwave Background radiation. The CMB has been produced about 380,000 years after the Big Bang. Giving that the space is flat as many observations suggest, that radiation has been produced in a universe with no boundaries.   Now, my question is this: in these conditions, why that radiation has not been dispersed completely so far? It is true that the radiation has been produced everywhere in the space but giving that the space is infinite, why has not it been dispersed do far?   Calculations in the standard textbooks are done in such a way as if the CMB has been within a physical box, however expanding with the universal expansion. But, this is not the actual situation. The CMB has not been and is not enclosed by walls of a box, so it must have completely dispersed so far. What has prevented this to happen? How to convert a HEIF/HEIC image to JPEG in El Capitan? So, here’s the thing. I have a new iPhone and an old Mac. iOS 11 (still in beta as of today) and El Capitan (no more updates for this Mac). I use iCloud photo library in both devices. When I take a photo in the new format with my iPhone 7, is there any way to use it right away in my mac, without having to convert it in my iPhone first? I mean, can I get those photos synced through iCloud and converted locally on my Mac?  I have tried to find a third party software that could do that kind of conversion, but was not able to find any that would work on El Capitan. Any idea? Dollar signs breaks formatting of 'Hot Network Questions' Related to  and .  This :    looks like this in the 'Hot Network Questions' section of e.g. :    I think Latex formatting of question titles should be disabled if the question comes from a site that don't use Latex formatting. How to sort an array of integers correctly Decoupling capacitors: what size and how many? As per the title, what is this new feature? In The Dark Knight Rises, at the beginning of the film Bane kidnapped a guy from the plane, then he drew blood from the guy he kidnapped. And then throughout the movie I didn't see any news regarding this kidnap scene. But, before the end of the movie we find out that the guy kidnapped by Bane was Dr Pavel. Bane needed him to convert the fusion project into a nuclear bomb and Dr Pavel was the only guy who could have done it.   But I don't understand, why did he draw blood from Dr Pavel? How to sum a variable by group Check tag classes with watir? How to filter a list by hour Newcommand + Stepcounter I'm trying to come up with a command which should increase a counter and return a string including the current value of the counter.  Have a look at the following minimal example:  \documentclass{article}  \newcounter{mycounter} \newcommand{\mystepFAILS}{\stepcounter{mycounter}foo\themycounter} \newcommand{\mystepWORKS}{foo\themycounter}  \begin{document}  \section{\mystepFAILS}  \section{\mystepWORKS}  \end{document}   Why does the command with \mystepFAILS throw an error? What is so special about \stepcounter? Any ideas? Is circular reasoning always a fallacy? Every infinite subset of a countable set is countable. Here is the proof I tried to weave while trying to prove this theorem:     Theorem. Every infinite subset of a countable set is countable.      Proof. Let $A$ be a countable set and $E\subset A$ be infinite. Then $A\thicksim\mathbb{N}$. This implies that there is a sequence $\left\{x_{n}\right\}_{n\in\mathbb{N}}$ where $x_{n}\in A$. Construct a sequence $\left\{n_{k}\right\}_{k\in\mathbb{N}}$ where $x_{n_{k}}\in A$, $n_{1}$ is the smallest positive integer such that $x_{n_{1}}\in A$, and $n_{k+1}&gt;n_{k}$. Then      $$ E=\bigcup_{k=1}^{\infty}x_{n_{k}}, $$      and $E$ is countable, because $E\thicksim\mathbb{N}$. $\blacksquare$   Is it convincing? When an account is deleted, the username in the user's posts and comments is changed to a generic user&lt;userID&gt;. But the username stays the same on close and delete notifications on posts the user had voted to close / delete1. I think it shouldn't, especially for users who used their real name as their username, if they chose to distance themselves from the site and remove their accounts, it makes sense that they wouldn't really want their name plastered on close and delete notifications.   A perhaps easy way to avoid the actual username remaining visible would be to change it to the generic user&lt;userID&gt; (or anything generic enough, like "anonymous") prior to deletion, and wait a bit for the generic username to propagate all over the site. If I'm not horribly misreading , this was part of the process in the old days.   This could be automated or added as a suggestion to the .  Glaring example can be seen , where the deleted user also posted a comment where their name is properly anonymized:        1 I've seen it on close notifications and self deleted answers. I'm not sure it happens on deleted questions, or deleted answers that aren't self deletions, and I don't have a way to verify it - other than stumbling on them accidentally