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11:00 PM
25 mins ago, by Sir Cumference
For a function $f$ whose antiderivative is $F$, I always interpreted $\int{f(x) \mathrm{d}x}$ as canceling out the denominator in the antiderivative: $=\int{\frac{\mathrm{d}F}{\mathrm{d}x} \mathrm{d}x}=\int{\mathrm{d}F}$, and then summing up the differentials to get $F$. So, the integral sign is an operator that acts on differentials.
Where is the error in this logic?
 
$\int dF$ doesnt mean anything though
 
@Faust Of course it does, just as $\int{dx}=x+C$
 
for example let $dF(x) = 2x$
 
god, this discussion is cancer
2
 
Zee
i Come here to laugh at you all
 
11:03 PM
You're not any better
 
then your saying $\int 2x dx = \int x^2? $ or your saying $\int 2x dx = \int 2x $ but the $\int 2x = 2xy$ or $ x^2 ?$ what your writing down is nonsense
 
@Faust Why is your differential not written with respect to another differential
 
Zee
Am not better , am not even on the same axis
 
right, these guys at least have hope of doing something good
 
@Faust What?? I never said you can have an integral sign without a differential
$dF$ is a differential!
 
Zee
11:05 PM
idk What good they want to do but they sure are going about it the wrong way
Unless by good you mean someday write a math paper that nobody is gonna read
 
What are we fiting about
 
@BalarkaSen Tell me if this is logical
5 mins ago, by Sir Cumference
25 mins ago, by Sir Cumference
For a function $f$ whose antiderivative is $F$, I always interpreted $\int{f(x) \mathrm{d}x}$ as canceling out the denominator in the antiderivative: $=\int{\frac{\mathrm{d}F}{\mathrm{d}x} \mathrm{d}x}=\int{\mathrm{d}F}$, and then summing up the differentials to get $F$. So, the integral sign is an operator that acts on differentials.
 
alright if you understand thats great but whatever your writting down makes no sense to me good luck with it.
 
Sircumference has gone full retard but I have to defend him because we are hbar brothers
 
@BalarkaSen ur face
 
11:06 PM
@0celo7 ...
I'm just trying to put together this fucking notation
What idiot invents notation that's illogical?
 
@SirCumference At the cost of rigor, this makes sense.
 
0
Q: If sequence of vector spaces is exact then the sequence of duals is also exact

HerrWarumInduced Exact Sequence of Dual Spaces I was able to prove the result for short exact sequences, but my instructor did not say short exact sequence, just sequence. So it is not given that the maps in the sequence are injective or surjective. Is there a counterexample to the sequence of duals bein...

 
Math is supposed to be the good subject, unlike physics
 
help!
 
I don't see what the fight is about
@Daminark no u
 
11:08 PM
@BalarkaSen The fight is about this question
32 mins ago, by Sir Cumference
Suppose we have a double integral $\iint{f(x) \;\mathrm{d}x \mathrm{d}y}$. Would it be correct to interpret this as: $\iint{\frac{\partial^2 f}{\partial x \partial y} \;\mathrm{d}x \mathrm{d}y}$, cancel out the denominator, and view it as summing:
$\iint{\partial^2 f}$?
 
Oh no, that's a bit problematic.
Also did you mean $f(x, y)$
 
like I said, Larky
 
@BalarkaSen Yeah, sorry
 
Ok, no it gets problematic once you involve two or more variables. The rigorous context of this whole story lies in differential forms.
 
Zee
Nah , you need a product measure
 
11:10 PM
@Zee No, he wants to view the 2-form $f dxdy$ as an exact form.
This has nothing much to do with measures.
It's not a definite integral, so to speak
 
See @LeakyNun
 
All right, I'm going to go and sulk
 
Hello. Hello. Lovely day, yes?
 
whats the deifnition of an exact vector space
 
@SirCumference I'd explain the story to you in more detail but I need to go to sleep and won't have time for 2 weeks to have an extended discussion. Here's a suggestion: Ask @TedShifrin about it, and he will explain this in greater detail and more clarity.
 
11:12 PM
Welp all right, I guess I'll head out
 
I'm off to bed for now.
 
@Faust well actually its the sequence of linear maps thats called exact
if the image of one is the kernel of the next
exactly equal, you might say.
 
Zee
the Integral is simply an operator with the dx specifying the range space
 
@HerrWarum can you have more than two steps then?
 
@Faust oh yes. even infinitely many
An exact sequence is a concept in mathematics, especially in group theory, ring and module theory, homological algebra, as well as in differential geometry. An exact sequence is a sequence, either finite or infinite, of objects and morphisms between them such that the image of one morphism equals the kernel of the next. == Definition == In the context of group theory, a sequence G 0 → f 1 ...
 
11:16 PM
wierd seems its outside of my level of understanding sorry ^^
are they applied to the range or to the whole space each time?
 
Find and solve the appropriate congruences.
Anklebiters Childcare Centre bought t toys. The toys came in packs of 10. The next day, at the start
of the day there were n children at the centre. The children were evenly divided into groups of 4, and
each group was given 6 toys. There were 2 toys left unused. Two toys were destroyed by the children’s
brutal style of play and had to be thrown out. Later on, m more children were dropped at the centre.
The children were then divided into groups of 6, with 7 toys per group. There were 6 (intact) toys not
 
@Faust I don't understand what you are trying to say. Yes each map is defined on the entire space each time just with the restriction that its kernel is the image of the previous one and its image is the kernel of the next one. Does that answer your question?
 
m/6 *7 -10t =8. and n/4 * 6 -10t =2
m+n = 6x n=4y
@HerrWarum yes it makes sense thats why u cna have more than 2 :p
 
Yes, looks like you're the right track, and yes I'm working with mod 10.
you're on*
 
you cant find t ans a given number
you can only find t as some number plus a multiple of anthor number
 
Zee
11:32 PM
@Daminark so are you becoming an algebraic geometer?
 
oh never mind i figured it out
 
No idea what I'm doing. I haven't really seen enough AG to say
 
hi chat
 
So far though, I think I've resonated best with algebra and what I've seen in topology
 
Zee
@Daminark I kinda empathize with what you said about differential geometry and physics
 
11:34 PM
n=48
 
Yeah, I'll try Gromov-style stuff and other branches of geometry at some point as well, they do seem fun
But diffgeo of the sort that I saw... I'm giving an extended break
 
guys i have a small question
 
Zee
@Daminark ya , same , it was like glorified calculus
 
F : V---> Reals, a linear map, we assume ker F does not equal to V, need to show that every element of V can be written as k+cv
k is an element in the kernel
c is a number of the field
 
252
 
11:39 PM
am not sure waht exactly they ask for here
 
@DarkVampiricAbstractArtist 252 children
 
I get that F( k+cv) = cF(v) but why each element of v can be written as a sum or element of the kernel and constant multple of it
 
Woah, how did you got there fast?
 
Zee
Idk if I understand your question, but you have f(v) = 0 + 1 f(v) = f(1 v + k)
 
@Zee I get that part but , what make us conclude that v = v+k
i mean f (a) = f(b ) does not mean a =b
unless we have injetive funtion but that was not given
 
11:42 PM
I'll check if I have gotten the same result as you @Faust but thanks anyways :).
 
first you can verify that the smallest number that makes sense for n is 48 next you need 42x -10t -2 =6 or 42x -10t =8 this will happen when 42x ends with a 2 so start summing the first last digit is 2, then 4, then 6,8,10,12 cause we want to end with a 2 so we have 6 * 42 =252
@DarkVampiricAbstractArtist
 
Zee
Is v fixed here ?
 
I would assume that
in the question it was called v_0
 
notice that $x=1$ or $42$ is not a solution because $n =48 > 42$ at minimum @DarkVampiricAbstractArtist
 
No idea what is the point of this question ._.
 
Zee
11:44 PM
Idk , I don’t think v is fixed
 
I do get that the set of elements that get mapped to F(v) is v+kerF
should I type the question verbatim ?
 
Zee
Maybe let k=0 and c=1
Ya go ahead
 
Let V be a vs and F :V---> R a lin map , Let W be the subset of V consiting of all elements v such that F(v) = 0, assume W does not equal V. and let v_0 be an element of V which is not in W
show that evry element of V can be written as a sum w+cv_0
w is some element of W and c is some number
one usually denote "v_0" to mean fixed element but i dotn see how that would make sense here
@Zee
 
Zee
If we allow v_0 to be varying but still outside of W then it’s trivial
 
that what i thought too
 
Zee
11:50 PM
Perhaps it is that trivial...
 
is R the field?
 
its pretty trival
 
hmm i dont know why am not convinced ><
 
what is W?
 
11:51 PM
there is like no way that each element of V can be written as some fixed element v_0 + stuff from the kernel
W is the kernel of F
 
ok good you know its the kernel.
 
faust I can allways count of you on such remarks :D
 
Zee
Ya I think it’s just what you thought
 
@0celo7 can we be friends for 5 minutes?
 
but zee
 
11:55 PM
or anyone else who knows diff geo for that matter? can we be friends for 5 minutes?
i'm not limiting our relationship to that time period
 
am still not convinced even if we carry v
 
i just really need a favor
 
because T(cv+w) = cT(v)
 
Zee
Am still learning the basics of diff geo but you can ask
 
+ T(w)
 
11:56 PM
this does not mean that cv+w = v
 
Zee
W is a kernel element joe
 
um, no i need a specific question
oh ok
 
i didn't read the whole convo. i was just being a jerk
:)
 
Zee what forces v = cv+w ?
makes not sense to me
they do have same image but they are not equal
 
11:57 PM
right no
it all makes sense
dur. thanks for the help @Zee!
 
Zee
Khaan, I think it’s really this easy , if V is in the kernel then just let V= V + 0V, of V is not in the kernel then let V= 1 V +0
 
let $w_1, ... ,w_k$ be a basis for W extend ti to a basis for V so $ w_1,...,w_k,v_{k+1}, ... v_{n} $ then $W^{c} $ is a such that $V= W \oplus W^c $ where $v_{k+1},..., v_{n} $ is a basis for $ W^c $ now you need to show that $ W^c $ is a generalized eigenspace
 
Zee
Maybe am completely wrong but maybe it’s that easy
 
all righty =p thanks :)
 
its slightly harder
 

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