I have just started using QGIS 3.4 and want to split a polygon with a line from another layer. I can do this in 2.18 but there is no option in 3.4  Is this correct, is the tool not available
I am trying to split a selected polygon ("regions") with a selected line from another layer ("streets") in QGIS 3.8.3. In the example below, I want to split the selected polygon coloured in yellow with the street pointed at by the blue arrow.    After reading the post , I realized I can't find it either. I installed the plugin, but the tool seems to be missing from my toolbar:
Prove that $f$ analytic, $f(x) \in \mathbb{R}$ for all $x \in \mathbb{R}$ implies $f(\overline{z})=\overline{f(z)}$ Let $U\subset \mathbb{C}$ be a nonempty connected open set such that for every $z\in U$, $\overline z\in U$.  Let $f$ be analytic on $U$. Suppose $f(x)\in\mathbb R$ for every $x\in U\cap\mathbb R$. Prove that $f(\overline{z})=\overline{f(z)}$ for any $z \in U$.    By definition, I know that $f$ analytic on $U$ means that for every $z_0 \in U$, there exists $r&gt;0$ and a sequence of complex numbers $\left(a_n\right)_{n=0}^\infty$ such that $f(z)=\sum_{n=0}^\infty a_n\left(z-z_0\right)^n$ on the disc $D(z_0,r)\subseteq U$. I see that $f$ takes points without imaginary components to other points without imaginary components. But I don't see how this implies a symmetry that $f(\overline{z})=\overline{f(z)}$ for $z \in \mathbb C \setminus \mathbb R$. It seems like a very strong conclusion and I'm not sure how I would prove it.  I have also shown in the preceding question that $U\cap\mathbb R$ contains an open interval, however I am not sure if that detail is meant to be helpful to this question. Why $9$ & $11$ are special in divisibility tests using decimal digit sums? (casting out nines & elevens) I don't know if this is a well-known fact, but I have observed that every number, no matter how large, that is equally divided by $9$, will equal $9$ if you add all the numbers it is made from until there is $1$ digit. A quick example of what I mean:  $9*99 = 891$ $8+9+1 = 18$ $1+8 = 9$  This works even with really long numbers like $4376331$ Why is that? This doesn't work with any other number. Similarly for $11$ and alternating digits sums. Best File Management Practices when you have thousands of Files What are the basis for co-countable and co-finite topologies Injection from $\mathbb{N}\to\{0,1\}$ to the set of all monotonic decreasing functions from $\mathbb{N}\to\mathbb{Z}$ Are there perfect elastic collisions in Nature? Slow BIOS bootup This is a new HP DV-7 laptop. When you turn it on SOMETIMES it will wait at 15 minutes on the press escape for menu and sometimes it will boot correctly.  IS this a hardware failure issue or is this a new for a BIOS update? I am confused with the grammar here. Which is grammatically correct?       At which time will you call me?     At what time will you call me?    And why? Do we ever get more information about the Entwives? During my recent re-reading of The Two Towers I was struck again by a question that has bothered me since I was a youngling: What on earth is up with the Entwives?  Treebeard says they went away in the distant past and just... got lost?  Did Tolkien ever make mention of them again, or is this one of those unsolved mysteries of Middle Earth? Is it possible to remove a user's password using the net command?  I tried "net user &lt;name&gt; *" and just hitting return twice, but this does not work as expected. Is there any other way to do this? (I'd gladly take non-net commands, as long as they are built-in in XP SP3).  Edit: Seems, I did not make my intention clear. I don't just want to change the password, but remove it completely (so that the user may log in without having to supply a password).  I'm familiar with the "net"-reference and have searched online for several hours, but could not find a hint on how to do this. $E|X-m|$ is minimised at $m$=median For a continuous random variable $X$, I want to show that $E|X-m|$ is minimum implies $m$ is the median of the distribution. Assume that the distribution function is $F$ and the density function is $f$.  In this case, we basically need to minimize  $$\int_x |x-m|f(x)\,dx=\int_{x&gt;m}(x-m)f(x)\,dx+\int_{x&lt;m}(m-x)f(x)\,dx.$$  I am finally being left with $2mF(m)-m+E(X)-2\int_{x&lt;m}xf(x)\,dx$. What does it mean to minimise this expression? Is there some way out?  Well, my intuition says that since I have to prove that $F(m)=0.5$, I somehow will need to show that $E|X-m|$ is minimised if $2mF(m)-m=0$ (as then I will get $F(m)=0.5$ What is the difference between find . and /home/user/* as an input to for command.? For example:  for var in $(find .) do echo "$var" done   or  for var in /home/user/* do echo "$var" done   In the first case for command breaks up the file with names containing spaces. While in the second case it does not. Why? What do repeating '^@' symbols in a logfile mean? A few times I have come across this in a log file:  Sep 17 09:35:57 00187d378926 ovpn-00187d378926[1701]: /sbin/ifconfig tun0 0.0.0.0 Sep 17 09:35:57 00187d378926 kernel: Kernel logging (proc) stopped. Sep 17 09:35:57 00187d378926 rsyslogd: [origin software="rsyslogd" swVersion="4.6.4" x-pid="1707" x-info="http://www.rsyslog.com"] exiting on signal 15. ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@ ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@ ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@   What does it mean?  Sometimes it is a single line, other times it is lots of lines.  I usually see it happen on Debian 6 machines. I'm using an API that requires me to pass a function pointer as a callback. I'm trying to use this API from my class but I'm getting compilation errors.   Here is what I did from my constructor:  m_cRedundencyManager-&gt;Init(this-&gt;RedundencyManagerCallBack);   This doesn't compile - I get the following error:      Error  8 error C3867: 'CLoggersInfra::RedundencyManagerCallBack': function call missing argument list; use '&amp;CLoggersInfra::RedundencyManagerCallBack' to create a pointer to member   I tried the suggestion to use &amp;CLoggersInfra::RedundencyManagerCallBack - didn't work for me.   Any suggestions/explanation for this??  I'm using VS2008.  Thanks!! Prove Quotient Group Isomorphism Let $G = (\mathbb{C} - \{0\}, \cdot)$, a subgroup $U = \{x+yi \mid x^2 + y^2 = 1\}$. Use the Fundamental Theorem to show that $G/(\mathbb{R}_{&gt; 0},\cdot)$ is isomorphic to $U$ where $\mathbb{R}_{&gt; 0}$ denotes the positive reals.  I am struggling to find the correct mapping from $G$ to $U$ that results in the the kernel being the nonnegative reals under multiplication. I'm hoping to get help with this mapping then I can show it is a homomorphism and onto and can use the Fundamental Theorem. The StackExchange™ MultiCollider SuperDropdown™ says I've got replies, but I've already viewed those. I have noticed for a few months that my mouse will randomly jerk across the screen. I'm super paranoid about security. But this is just silly!  Has anyone else experienced this, and found out what causes it? It happens to me every couple of days. The cursor will jump across the screen about 1000+ pixels. I thought it was my mousepad - changed it, and that's not it.  I imagine it's just a hardware issue.  This is on a PC with a Razer Naga, wired mouse. The mouse worked for about a year before I started noticing these issues. They have persisted even after a reformat / reinstall. How to convert a column number (e.g. 127) into an Excel column (e.g. AA) Decomposition of the tensor product $\mathbb{Q}_p \otimes_{\mathbb{Q}} \mathbb{Q}[i]$ into a product of fields I am trying to solve the following problem:     For each rational prime $p$, describe the decomposition of the tensor product $\mathbb{Q}_p \otimes_{\mathbb{Q}} \mathbb{Q}[i]$ into a product of fields, where $\mathbb{Q}_p$ is the field of $p$-adic numbers.    I know that the tensor product of $2$ extensions of a field one of which is finite is Artinian and is therefore a product of Artinian local rings, but I do not know how to compute these Artinian local rings. Please if you can help me with this, I'll really appreciate it. We are having issues with our exchange 2013 server. The server is running Windows Server 2008 R2 Standard.  The issue we're having is that our Exchange server isn't receiving internet emails. It can currently send mail out to internet addresses, and send and receive internal emails from the current email server. I have checked the settings of the receive connectors and everything seems correct. We have tried everything that we can think of.   We can send and receive email locally, and send out to a gmail account. However, we don't get the reply email from the gmail account to the inbox.    Thanks in advance!! Image is of the DNS settings on the exchange server.