Attempt to invoke virtual method 'void android.database.sqlite.SQLiteDatabase.execSQL(java.lang.String)' on a null object reference
What is a NullPointerException, and how do I fix it?
About 'start' and 'begin' Are 'begin' and 'start' interchangeable? Both &quot;This is a new start&quot; and &quot;This is a new beginning&quot; work, right? Then during games, they say &quot;Let's start&quot;, but I never heard &quot;Let's begin&quot;. So is there supposed to be a difference? And then one guy said this &quot;They could not begin to start a conversation&quot;. What is this supposed to mean? Is it correct? $x,y,z \in \mathbb R$ My attempt: Notice that if $x^2 + y^2 + z^2 \geq xyz$ and $x+y+z \geq xyz$. So : $$x^2 + y^2 + z^2 \geq x+y+z $$ But this is actually not always true, take the case when $ 0&lt;x,y,z &lt;1$ And you will see that this is not working. Maybe I’m wrong. Split a string with delimiters but keep the delimiters in the result in C# How can I update youtube-dl? I'd like to "add to" an existing command by writing something like  \renewcommand{\somecommand}{\begin{something}\somecommand\end{something}}   but (not surprisingly) I get errors about being "too deeply nested".  Is there a way to take an existing command, add to it (by appending or prepending additional commands or text), and then have that "augmented" command replace the existing command? Possible Duplicate:          This is a line spoken by the . I always wondered if this is grammatically correct.  Luke says something like "You are mistaken ..." which the Emperor answers with     No, it is you who are mistaken!   Why wouldn't he say     No, it is you who is mistaken!   instead?  I don't know what rules apply here but my stomach tells me the latter is (at least also) correct, although you would say "you are mistaken". It feels as if he should be referring to "you" in the third person.  Could you please shed some light? Are both correct or – if not – which one is correct? And why? Probability for roots of quadratic equation to be real, with coefficients being dice rolls. I really need help with this question.     The coefficients $a,b,c$ of the quadratic equation $ax^2+bx+c=0$ are determined by throwing $3$ dice and reading off the value shown on the uppermost face of each die, so that the first die gives $a$, the second $b$ and and third $c$. Find the probabilities that the roots the equations are real, complex and equal.   I was thinking about using the fundamental formula but i'm not sure how to go about doing it. Help would be greatly appreciated. How can I make calls related to a case display in its Chatter feed? I am using the Service Console in Lightning Experience, and using the Chatter Feed component on the Case layout to display updates to the Case.  If I use the "Log a Call" Quick Action from the Chatter publisher, these calls are displayed in the Chatter feed.  This is the desired behaviour.  However, if I insert a Log a Call record related to the Case any other way - e.g. using the Developer Console, or my CTI system's custom components - the call does not display in the feed.  If I query the record, it looks exactly the same as the record that is created with the Quick Action.  It just seems that the Chatter post is never made in this situation.  I have checked my Feed Tracking settings:   Task has Enable Feed Tracking and Subject checked Case has All Related Objects checked   How can I enable calls created with a custom component (part of a CTI system) to display in the case feed? Your favourite application of the Baire Category Theorem The Tree of Life in Evangelion I've noticed references to the Kabbalah in a couple of anime I've watched.  One of them is Neon Genesis Evangelion.  Neon Genesis Evangelion has it in the sky in both the opening credits and in the series itself:     I also remember it was on the ceiling at NERV, but the best screencap I could find of that was too tiny to be visible.  So, my question is, Is there any deeper meaning to the use of the Kabbalistic tree of life, or is it just used because it looks cool? Is it just that nvarchar supports multibyte characters? If that is the case, is there really any point, other than storage concerns, to using varchars? A hidden process, what it is? [root@datacenteronline ~]# ssh root@192.168.1.172 Last login: Wed Apr 17 09:55:45 2013 from 192.168.1.187 [root@localhost ~]# ls /proc/ | grep 2266 [root@localhost ~]# cd /proc/2266 [root@localhost 2266]# ls attr             cpuset   limits      net            root       statm autogroup        cwd      loginuid    numa_maps      sched      status auxv             environ  maps        oom_adj        schedstat  syscall cgroup           exe      mem         oom_score      sessionid  task clear_refs       fd       mountinfo   oom_score_adj  smaps      wchan cmdline          fdinfo   mounts      pagemap        stack coredump_filter  io       mountstats  personality    stat [root@localhost 2266]# ls -al /proc/2266 total 0 dr-xr-xr-x   7 apache apache 0 Apr 17 09:45 . dr-xr-xr-x 266 root   root   0 Apr 17 09:11 .. dr-xr-xr-x   2 apache apache 0 Apr 17 09:45 attr -rw-r--r--   1 root   root   0 Apr 17 09:45 autogroup -r--------   1 root   root   0 Apr 17 09:45 auxv -r--r--r--   1 root   root   0 Apr 17 09:45 cgroup --w-------   1 root   root   0 Apr 17 09:45 clear_refs -r--r--r--   1 root   root   0 Apr 17 09:45 cmdline -rw-r--r--   1 root   root   0 Apr 17 09:45 coredump_filter -r--r--r--   1 root   root   0 Apr 17 09:45 cpuset lrwxrwxrwx   1 root   root   0 Apr 17 09:45 cwd -&gt; / -r--------   1 root   root   0 Apr 17 09:45 environ lrwxrwxrwx   1 root   root   0 Apr 17 09:45 exe -&gt; /usr/local/apache2/bin/httpd dr-x------   2 root   root   0 Apr 17 09:45 fd dr-x------   2 root   root   0 Apr 17 09:45 fdinfo -r--------   1 root   root   0 Apr 17 09:45 io -rw-------   1 root   root   0 Apr 17 09:45 limits -rw-r--r--   1 root   root   0 Apr 17 09:45 loginuid -r--r--r--   1 root   root   0 Apr 17 09:45 maps -rw-------   1 root   root   0 Apr 17 09:45 mem -r--r--r--   1 root   root   0 Apr 17 09:45 mountinfo -r--r--r--   1 root   root   0 Apr 17 09:45 mounts -r--------   1 root   root   0 Apr 17 09:45 mountstats dr-xr-xr-x   6 apache apache 0 Apr 17 09:45 net -r--r--r--   1 root   root   0 Apr 17 09:45 numa_maps -rw-r--r--   1 root   root   0 Apr 17 09:45 oom_adj -r--r--r--   1 root   root   0 Apr 17 09:45 oom_score -rw-r--r--   1 root   root   0 Apr 17 09:45 oom_score_adj -r--r--r--   1 root   root   0 Apr 17 09:45 pagemap -r--r--r--   1 root   root   0 Apr 17 09:45 personality lrwxrwxrwx   1 root   root   0 Apr 17 09:45 root -&gt; / -rw-r--r--   1 root   root   0 Apr 17 09:45 sched -r--r--r--   1 root   root   0 Apr 17 09:45 schedstat -r--r--r--   1 root   root   0 Apr 17 09:45 sessionid -r--r--r--   1 root   root   0 Apr 17 09:45 smaps -r--r--r--   1 root   root   0 Apr 17 09:45 stack -r--r--r--   1 root   root   0 Apr 17 09:45 stat -r--r--r--   1 root   root   0 Apr 17 09:45 statm -r--r--r--   1 root   root   0 Apr 17 09:45 status -r--r--r--   1 root   root   0 Apr 17 09:45 syscall dr-xr-xr-x  29 apache apache 0 Apr 17 09:45 task -r--r--r--   1 root   root   0 Apr 17 09:45 wchan   Cound anyone tell me what it is? Show that the function $f: S \to \mathbb R$ given by $$f(x,s,t):=-\ln(st - ||x||^2)$$ is convex on $$S := \left\{(x,s,t) \in \mathbb R^n \times \mathbb  R \times \mathbb R: \frac{\|x\|^2}{s}&lt;t, s&gt;0, t&gt;0 \right\}$$   $-\ln(x)$ is a convex monotonic decreasing function, hence we can use composition by showing the inner part is concave. Also we know $-||x||^2$ is concave and $st$ is neither convex nor concave on $S$. Also in $S$ we have $st&gt;||x||^2$ but I was unable to show the convexity of the function as a whole Create a tar archive split into blocks of a maximum size I need to backup a fairly large directory, but I am limited by the size of individual files. I'd like to essentially create a tar.(gz|bz2) archive which is split into 200MB maximum archives. Clonezilla does something similar to this by splitting image backups named like so:  sda1.backup.tar.gz.aa sda1.backup.tar.gz.ab sda1.backup.tar.gz.ac   Is there a way I can do this in one command? I understand how to use the split command, but I'd like to not have to create one giant archive, then split it into smaller archives, as this would double the disk space I'd need in order to initially create the archive. $X$ is a random variable, if $\Bbb E(X^2)=1$ and $\Bbb E(X)\geq a>0$, prove that $\Bbb P(X\geq\lambda a)\geq(a-\lambda a)^2$ for $0\leq\lambda\leq 1$. This is a problem in KaiLai Chung's A Course in Probability Theory.     Given a nonnegative random variable $X$ defined on $\Omega$, if $\mathbb{E}(X^2)=1$ and $\mathbb{E}(X)\geq a &gt;0$, prove that $$\mathbb{P}(X\geq \lambda a)\geq (a-\lambda a)^2$$   for $0\leq\lambda \leq 1$.   Let $A=\{x\in \Omega:X(x)\geq \lambda a\}$, we get $$\int_A (X-\lambda a)\geq a-\int_A\lambda a -\int_{A^c}X$$ and $$\int_A (X^2-\lambda^2 a^2)=1-\int_A\lambda^2a^2-\int_{A^c}X^2$$ I want to contrast $\int_A (X-\lambda a)$ and $\int_A (X^2-\lambda^2 a^2)$, but I don't know how to do it, could anyone gives me some hints? Story about lost colonized planet sent into orbit around "free" star How to debug a Custom Timer Job in SharePoint 2010? I'm trying to build a datapack that lets you craft xp bottles from glass bottles at the expense of 7 xp per bottle (because they drop 3 to 11 xp so the average is 7). I have almost everything working except for a check for if they have too little xp. If they have 7 or less xp, I would like to remove one bottle of enchanting from their inventory and give them one glass bottle, because the function for removing xp is called after they've crafted one and a scoreboard has counted it. My remove function currently looks like this:  #create dummy scoreboard to multiply bottles crafted by seven to get xp to be removed scoreboard objectives add 7xp dummy scoreboard players set @s 7xp -7 scoreboard players operation @s xpCrafted *= @s 7xp  #how do I get the value in xpCrafted into the command to remove xp? xp add @s -7 points  #cleanup scoreboard players reset xpCrafted scoreboard players reset 7xp scoreboard players set @e xpCrafted 0 scoreboard objectives remove 7xp   And my tick function like this:  execute as @e[scores={xpCrafted=1..}] at @s run function craft_xp:removexp   As the inline comment says, how do I get that value in xpCrafted into my xp removing command, and also how should I check to make sure the player has enough xp for the operation in the tick command (or elsewhere)? Presumably I would run a different command to remove the extra bottle if they didn't have enough xp, but I don't know how because there doesn't seem to be any type of if/else structure in commands. Finally, should a question like this be in two different questions or is one ok on this forum? Show that $d_2$ defined by $d_2(x,y)=\frac{|x-y|}{1+|x-y|}$ is a metric I am pretty sure that this is such a stupid, stupid question, but how do you prove that $d_2(x,y)={|x-y|\over {1+|x-y|}}$ satisfying the third condition to be a metric, which is the triangle inequality.   I know that I should really be able to do this, but I just can't, I keep seeing a contradiction. Please help me. If $\operatorname{rank}\left( \begin{bmatrix} A &B \\ C &D \end{bmatrix}\right)=n$ prove that $\det(AD)=\det(BC)$