how to install Jdk 7 on ubuntu 12.04
How can I install Sun/Oracle's proprietary Java JDK 6/7/8 or JRE?
Where are the developer options in Android 4.2? extract string between double quotes I have requirement that i need to extract string using quotes. My string as follows.  "abcd efgh" "ijkl mnop" "qrst uvwxyz"   can you help me to get the string between second double quotes(ijkl mnop) using sed or grep command.  In other words if I say give me the string in first quotes I want the  first string; if I say second string it should give me string between second double quotes and similarly third one also. If the positive series $\sum a_n$ diverges and $s_n=\sum\limits_{k\leqslant n}a_k$ then $\sum \frac{a_n}{s_n}$ diverges as well So I've been trying to figure out how to prove the following.     Let $(a_n)$ be a sequence of positive numbers such that $\sum\limits_{n=1}^\infty a_n =\infty$, and define $s_n=\sum\limits_{i=1}^n a_i$. Then $\sum\limits_{n=1}^\infty\frac{a_n}{s_n} =\infty$ as well.   I can prove it by comparing it to $\int_1^\infty \frac{1}{x} \, dx $ if the sequence $a_n$ is bounded by some $M$, but that's as far as I've been able to get. Footnotes in tables? I would like to have footnotes in tables, but the \footnote command does not work inside a table environment.  Googling one finds that this is , at least in the UK.  That link contains a list of solutions to the problem, but since the author of the FAQ does not believe that this is good style, no comparison is made between the different methods.  I am sure that there are good typographical reasons why in most situations it is undesirable to have footnotes in tables (although I have never come across them), however I have recently felt the need to do just this in a paper I am currently writing.  Therefore I'd like to ask two questions:   What are the arguments against footnotes in tables? If one really must go against the advice in 1., which method (whether considered in the  or not) would you recommend?   Thanks in advance.  Added  In response to ShreevatsaR's comment: I do not much care for where the text of the footnote appears.  I do however insist on the footnote marks being attached to the relevant entries in the table, so that I can avoid having to reference "the second entry in the eighth line of the table", etc... Some things I know:  omega_1 is the first uncountable ordinal, made up of all of the countable ordinals f is not necessarily continuous    For this proof, I currently have x as a condensation point in my range, and I know that (x - (1/n) , x + (1/n) ) is uncountable and everything to the left and right of this interval is countable. I understand that I want to shrink this interval small enough just to x (which will be my constant), making everything around x eventually countable. I also understand that this will eventually make all of the elements in omega_1 go to x but I am having a hard time seeing where my contradiction comes in. I also am struggling with writing this proof in a presentable fashion.   Thank you! Homeomorphism is bijective Here is my question:  Is a homeomorphism, that is, a continuos function whose inverse function is also continuous, always bijective? Extreme cursor delay with Acer Aspire E15 on Ubuntu 16.04 Occasionally my laptop will enter a state where the cursor starts lagging so bad that it's unusable.  Oddly during this state, everything other than the cursor is still completely responsive.  I.e. anything that only involves the keyboard (opening a terminal, typing, etc) is unaffected.  Once it enters this state, on successive reboots and shutdowns it re-enters this state within seconds.  However, if I shutdown and leave it alone for a few minutes, it does not immediately re-enter this state.  Based on search results for "acer aspire ubuntu freeze" I have tried setting the intel_idle_max_cstate field in grub to 0, 1, and 2, but this did not seem to help.  To be clear - I am not experiencing any crashes, the system is completely responsive except for the cursor is delayed to the point where it would take several seconds to go from one edge of the screen to the other. How is $\dfrac1{(1-x)^5}=\sum_{n\geq0}{n+4\choose4}x^n$ Can someone please explain to me how is $$\dfrac1{(1-x)^5}=\sum_{n\geq0}{n+4\choose4}x^n$$  Thanks! Where can I see my full list of Questions and Answers in my profile page of Stack Exchange Android App? I want to see all my Questions and Answers in a particular SE site -  - profile page through Stack Exchange Android App. How can I see that? When I tried to see that I found only Top Posts(5) and Top Tags. Why couldn't Harry see Thestrals at the end of Goblet of Fire after the senseless and shocking death of Cedric Diggory?   At the end of Goblet of Fire, the carriages still appeared horseless to Harry:     Hermione turned away, smiling at the horseless carriages which were now trundling towards them up the drive, as Krum, looking surprised, but gratified, signed a fragment of   parchment for Ron.   Goblet of Fire - Page 629 - British Hardcover - Adult Edition   At the beginning of Order of the Phoenix, Harry sees the Thestrals for the first time:     Here stood the hundred or so horseless stagecoaches that always took the students above first year up to the castle. Harry glanced quickly at them, turned away to keep a lookout for Ron and Hermione, then did a double-take.   The coaches were no longer horseless. There were creatures standing between the carriage shafts.   Order of the Phoenix - Page 178 - British Hardcover - Adult Edition   We know that only those who have seen death can see Thestrals:     ‘Don’ worry, it won’ hurt yeh,’ said Hagrid patiently. ‘Righ’, now, who can tell me why some o’ yeh can see ’em an’ some can’t?’   Hermione raised her hand.   ‘Go on then,’ said Hagrid, beaming at her.   ‘The only people who can see Thestrals,’ she said, ‘are people who have seen death.’   ‘Tha’s exactly right,’ said Hagrid solemnly [...]   Order of the Phoenix - Page 394 - British Hardcover - Adult Edition   A month went by between Cedric's death and the end of the spring term -- is this enough time for Harry to have truly internalized Cedric's death? Goblet of Fire indicates that Harry was in shock following Cedric's murder, but was able to relate the story of Cedric's death to Mr. and Mrs. Diggory.     When he looked back, even a month later, Harry found he had few memories of the following days. It was as though he had been through too much to take in any more. The recollections he did have were very painful. The worst, perhaps, was the meeting with the Diggorys that took place the following morning.   [...]   ‘He suffered very little, then,’ she said, when Harry had told her how Cedric had died.'   Goblet of Fire - Page 621 - British Hardcover - Adult Edition   So, then, why couldn't Harry see Thestrals at the end of Goblet of Fire? Taylor Series type inequality Characterizing units in polynomial rings I am trying to prove a result, for which I have got one part, but I am not able to get the converse part.  Theorem. Let $R$ be a commutative ring with $1$. Then $f(X)=a_{0}+a_{1}X+a_{2}X^{2} + \cdots + a_{n}X^{n}$ is a unit in $R[X]$ if and only if $a_{0}$ is a unit in $R$ and $a_{1},a_{2},\dots,a_{n}$ are all nilpotent in $R$.  Proof. Suppose $f(X)=a_{0}+a_{1}X+\cdots +a_{n}X^{n}$ is such that $a_{0}$ is a unit in $R$ and $a_{1},a_{2}, \dots,a_{r}$ are all nilpotent in $R$. Since $R$ is commutative, we get that $a_{1}X,a_{2}X^{2},\cdots,a_{n}X^{n}$ are all nilpotent and hence also their sum is nilpotent. Let $z = \sum a_{i}X^{i}$ then $a_{0}^{-1}z$ is nilpotent and so $1+a_{0}^{-1}z$ is a unit. Thus $f(X)=a_{0}+z=a_{0} \cdot (1+a_{0}^{-1}z)$ is a unit since product of two units in $R[X]$ is a unit.   I have not been able to get the converse part and would like to see the proof for the converse part. Do multi-use keys get discarded when finished with? As with many resident evil games, you sometimes needs to collect certain keys to open certain doors, and resident evil 7 has plenty of these around.  Some keys are clearly single use, and get left in the lock in which you use them. However, there are a number of keys that can be used on multiple doors. For example, the Scorpion Key.  I am concerned that I might end up carrying these around needlessly and using up valuable inventory space, so...  Do these multi-use keys get discarded when you use them on all the doors they apply to? Or do you get a warning saying the key is no longer needed? (like previous games are known to do) Getting text from the Resource file in asp.net 4 What is a "double date"? How do I recover lost/inaccessible data from my storage device? Which sort algorithm works best on mostly sorted data? I am a Pakistani national and need to transit through Dubai International Airport (DXB).  I am not planning to leave the airport and both of my flights (arrival and departure) are from Terminal 3.  I am pretty sure that I do not need transit visa at the DXB, however it is no where mentioned on any of their official website.   Can anyone please provide me such a link stating that transiting without leaving the airport does not require visa at DXB, as I need to use this link as a proof for a visa application?  Thanks Do downvotes on Meta truly mean something different? How to find an end point of an arc given another end point, radius, and arc direction? Given an arbitrary arc, where you know the following values: end point (x1,y1), radius (r) and arc direction (e.g. clockwise or counterclockwise from start to end), how can I calculate the other endpoint of the arc (and I say endpoint because I think of an arc as line segment that is curved, which happens to lie on the circumference of the circle and it has two end points).   Though that's just how I interpret the problem and maybe I'm not thinking about it correctly.  EDIT: Yes, I know the Origin point and the length of the arc. Sorry I forgot to mention. Also, the that circle would be on a 2D Cartesian plain (x and y axis.) Sorry, my math terminology is lacking.   Also, I'm not trying to cheat on homework or anything. This is a legitimate problem for an SVG graph I'm trying to create using JavaScript and I've tried my best but I need help.  Thanks in advance.