Mathematics, help needed!

titaniumx3 · 22 Oct 2007 at 22:15

I would really appreciate some help on this transform theory question. I have been at it all day but can't for the life of me figure out how to prove if the Fourier series converges (absolutely) or how it coincides with the given real series. From my lecture notes there are various theorems on convergence and I'm guessing I need to use Dini's Theorem but it doesn't seem to make any sense with regards to the function in question. Here is the question:

I've obtained the Fourier series but can't seem to progress any further.

Any help would be hugely appreciated!

lukechad · 22 Oct 2007 at 22:18

I dont think we have an area for loonies, that looks very complicated! I did my first year of A-level maths and thought that was tough! This is insane!

Sorry im no help here

JonC · 22 Oct 2007 at 22:26

Not done any maths for a couple of years, but I'm sure there are some who have. Give us the Fourier series, see where we can go from there.

eddie101 · 22 Oct 2007 at 22:30

The answer is 7.... Although i could be wrong......

lol

Sinque · 22 Oct 2007 at 22:35

That's what I read the question as.

What level is that?!

Wiggins · 22 Oct 2007 at 22:40

Inquisitor · 22 Oct 2007 at 22:41

Sinque said:
That's what I read the question as. What level is that?!

Second or third year undergrad at a guess

titaniumx3 · 22 Oct 2007 at 22:47

JonC said:
Not done any maths for a couple of years, but I'm sure there are some who have. Give us the Fourier series, see where we can go from there.

Well this is what I got for the Fourier series:

BTW, this is my third year and yes, it's f'ing hard.

Lagz · 22 Oct 2007 at 22:52

What uni/course is this? That question looks very familiar, hmm.

FrostedNipple · 22 Oct 2007 at 22:52

titaniumx3 said:
Well this is what I got for the Fourier series:

BTW, this is my third year and yes, it's f'ing hard.

is it as hard in 1st and 2nd year?

titaniumx3 · 22 Oct 2007 at 23:00

FrostedNipple said:
is it as hard in 1st and 2nd year?

1st is pretty easy so long as you put in a fair amount of study. 2nd get's harder since there is more emphasis on analysis and abstraction (with more proofs to do) but 3rd year just takes the urine, lol. That said, I've just started to sort my study routine out so things might get better.

I'm doing the single honours mathematics at university of birmingham, btw.

Sinque · 22 Oct 2007 at 23:02

I'm only doing graph equations, where I have to find the equation of the line

It's hard

Inquisitor · 22 Oct 2007 at 23:32

titaniumx3 said:
university of birmingham

I'm doing TPAM (first year)

Peter Diffey · 22 Oct 2007 at 23:51

We had to do fourier series in 2nd year of B Eng in mechanical engineering

Amleto · 23 Oct 2007 at 00:24

Inquisitor said:
I'm doing TPAM (first year)

I did that :cool:

. finished in 2003 though. get prepared to be hated my maths peeps, and physics peeps.

Inquisitor · 23 Oct 2007 at 00:26

Amleto said:
I did that . finished in 2003 though. get prepared to be hated my maths peeps, and physics peeps.

I'm already feeling the love

It's a small bunch of us doing it, but us TPAMers are better than everyone else so that's ok

Amleto · 23 Oct 2007 at 00:32

titaniumx3 said:
Well this is what I got for the Fourier series:

BTW, this is my third year and yes, it's f'ing hard.

do you know about the exp(ix) = cos(x) + isin(x) identity?

titaniumx3 · 23 Oct 2007 at 00:59

Amleto said:
do you know about the exp(ix) = cos(x) + isin(x) identity?

Yeah I tried that but it doesn't seem to go anywhere in regards to the series shown in the question.

Cold_And_Miserable · 23 Oct 2007 at 01:45

Maybe e^iPi = -1 could help?

Pi/2 -(2/Pi + 0 + 2/3Pi + 0 + 2/5Pi ....)*e^[n(x/Pi)] = ?
Pi/2 - 2/Pi(1 + 1/3 + 1/5 +1/7 ...)*e^[n(x/Pi)] =
The series of 1 + 1/3 + 1/5 ... has an infinite value I think.

James07 · 23 Oct 2007 at 01:51

Google tbh...

go to google and type define

the subject of relevance)

itll come up with descriptions, some links at the bottom etc... may help you out.