Okay, a makes a little bit more sense.

Im going to go see what I come up with, but it looks as though you have solved most of my issues

Thank you a bunch. You have been of great help.

~BD

French, people

I went to a concert:

Je suis allé au concert?
or
Je suis allé à un concert?

I need an answer real fast, I have a test in about 2 hours.

Thx, 1337man

you can still answer it if you want, but i don't need it anymore

Nailed the test: 8/10

Answered

French here too:P i need help, if someone can write about 10-15 sentences about the theme "Le Sport" in France, in french

Assuming le sport isn't any newspaper or magazine, but just normal sports: (excuse spelling, writing on my phone :p)

J'aime le foot, c'est mon sport favorit. Je joue le foot depuis 6 ans. Je joue dans une jolie equippe. L'annee passé, nous gagnions le competition (not sure if this sentence is correct). Je ne joue pas des autres sports, mais j'ai vu le tennis hier. Le match était tres bon. J'aime voir le rugby aussi. Je trouve que l'equippe française joue tres bien, mais l'equippe anglaise joue meilleur. Je n'aime pas l'equippe australienne, parce que ils jouaient tres mauvais.

I hope this helps, although it's random shit i just made up :p

If it was about a newspaper or magazine, D: but meh

Make sure you spellcheck it though.

Yours trolly,
1337man


P.S. sry bout the trolly, still excited bout my french mark

I have an army of Asian slaves to do my homework xP

Ill throw you a few sentences that you may be able to use in about 2 mins because I don't have much time:

If you wanna talk about sport's importance in france you say:

Le sport est omniprésent en France. En effet, le football est une passion que partagent de larges groupes d'individus, et nous pouvons même citer plusieurs grandes équipes de football ce qui montre que c'est un sport clef. D'autre part, il y a le tennis qui a une grand importance en France, car nous pouvons remarquer que durant les années il y eut plusieurs joueurs de renommée, comme par exemple Yannick Noah, Richard Gasquet, ou Gael Monfils. Un troisième sport qui a une grande place dans la nation francaise, est le rugby. Cette équipe, aussi nommé "le quinze de France" se place quatrième au rang mondial.

If you want to add a personal touch to this text say:

Personnellement, je préfère le football, car depuis tout petit je le pratique et aime l'esprit collectif et passionné de ce sport, qui est à la fois intriguant et plaisant.


To the other person it is : Je suis allé à un concert.


Also, In the spare time that I may browse this forums i will try to help as much as I can. You can ask me anything in these subjects : Spanish, French, Maths, Network Security, signal processing, computer science or communication based stuff.

Have fun.

Got my maths test in a few hours...was going over the past exams and came across a question where you have to use the result that
To find a basis for the row space of A, having already found the null space. I've been able to do it the other way around (I.e find the null space using that result having found the column space, but looking through the solution I'm a bit confused....
Heres a link to it (note its kind of big)
http://imgur.com/fxpTR.png

The part that confused me is where it says Inspection(!) gives... etc. I'm not sure how those solutions are obtained, other than just looking at the two equations and concocting a random solution for each one? Any help is appreciated

I'm sorry to have to tell you that the author is wrong. This is perhaps not what you wanted to hear an hour before your test, but I'll do my best to salvage the solution. It seems at least that the content of part (i) is correct. However, you will note that the two vectors he found "by inspection" are *not* perpendicular to the nullspace. While the first vector is perpendicular to the first basis vector of the nullspace, it's not perpendicular to the second. The same thing is true of the second vector and the first nullspace-basis vector. In short, the error occurred because the author did not actually solve the two equations in (ii) simultaneously; instead, he simply found a vector that satisfied each equation individually.

The way to actually solve this problem is to use the technique of row reduction that you are already familiar with to solve the underdetermined system (2 equations in 4 variables). This will give you a solution for two of the variables in terms of the other two. When I worked it out, I chose to solve for u_1 and u_2, giving

u_1 = u_3 + u_4
u_2 = 2 u_3 + u_4

Therefore, a possible answer is that the row space is the span of the following parametrized vector

(a + b, 2a + b, a, b)

as a,b range over all real numbers (a and b replacing u_3 and u_4 for brevity). You can then pick some nonzero values you like for a,b to produce a linearly independent pair of vectors whose span is the rowspace of A. For example, (1, 2, 1, 0) and (1, 1, 0 ,1) are clearly linearly independent and resulted from (a,b) = (1,0) and (a,b) = (0,1), respectively.

Ahhh! Thankyou very much , that was how I originally solved it, and became pretty confused when reading that answer...That clears it up, thanks again

Okay, I have a test coming up a few days in my Analysis class and I'm struggling a little with some of the problems.

The first one is define what it means for a set to be compact (ie every open cover has a finite subcover) and to define what it means for a subset to be closed (ie if its compliment is open) and to use these two to prove that in any metric space M, every compact subset A a subset of a metric space M is close.

Im just struggling with the last part.

The next I was having trouble with is whether or not the intersection of two compact subsets (A and B) of a metric M is also compact.

My thinking on this was that the intersection of two sets is a subset of those two sets. So, if we have an open cover C with a finite subcover C1 that covers A. Because A intersect B is a subset of A we can use C1 as a finite subcover of A intersect B and thus their intersection is also compact. Is this the correct thinking?

Also, the question asks if instead of a metric space we use R^n. I didnt think it would but maybe its a trick question?

Thanks
~BD

Bad sine. Use Google more often.
I got your entire answer by googling it and using a .gov site.

http://www.epa.gov/nitrousoxide/sources.html

You can also use Wolframalpha.com for chemicals. It has a surprising amount of information on loads of chemicals.

PS Wheres Anilv to guide me?

~BD

I hurt my hand playing goalie in a soccer game yesterday, so I don't feel like typing much. Here's an answer to your first question: http://answers.yahoo.com/question/index ... 047AAESOqE. The proof depends on the compactness of the subset because otherwise it would require taking an infinite union of open sets, which is not necessarily open. But yes, your definitions of compactness and openness are precisely the ones used in the proof.

For the second question, consider the following result: every closed subset of a compact set is compact. Why? Consider an open cover of the closed subset. That, together with the complement of the closed subset, forms an open cover of the entire compact set (complement of closed = open). But this open cover has a finite subcover, which in particular is a finite cover of the closed set. So the closed set is compact. This answers your question because the intersection of two compact sets in M is a closed set (intersection of two closed sets is closed), so it's a closed subset of each of the compact sets.

The compact subsets of R^n are precisely the subsets that are closed and bounded. Therefore, putting R^n in for M doesn't make a difference here.

Wouldn't the compliment of the closed subset be the entire metric space ,minus the subset itself? So that plus the open cover of the subset would just be the entire metric space?

Sorry you hurt your hand, you dont have to answer me if you wouldnt like to. Im sure Im bound to have more questions thought

Im only used to hurting my shins or ankles in soccer. Defense ftw!

~BD