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Take the courses. Think about what you're interested in (and also what's useful) and maybe don't do the minor, and just take other CS courses to supplement your goals/skills. You can always list a CS concentration or the CS courses on your resume instead of the minor.

Most math PhD students finish their degree in 5 years, doing not much else but studying maths and doing research. While I don't know your personal background, it's a little ambitious to assume you can do this in 5-6 years part-time, after being out of school for what I assume is 10 years. What...

Another way of thinking of this without resorting to too much probability. The HHH....TTT sequence is not unique, in that any other combination of H, T of length 12 should have the same probability of occurring and hence the same expectation. Since we only have 10^6-12+1 possible sets of 12, and...

I have been using Gmail since it debuted in beta. I've had no issue with YouTube emails, nor have i been forced to have a Google+ account. What am i missing here?

For VaR, most places I know go with a theoretical price, so you don't have to worry about piecing together price series.

I don't think this is a sufficient condition in general, all principal minors need to be be nonnegative. (In this case it may be sufficient).

Take original BS solution and replace mu and sigma with the new mu and sigma from the SDE for S^2.

Use Ito's lemma. X = S^2 follows GBM, so the payoff of max(X-K,0) has the same closed form solution as a plain vanilla options with the appropriate substitutions for drift and vol.

x=3n is true regardless of what x and n are, given your assumptions. If n is an integer, then x must be as well. In which case this function is not continuous. You can't assume it's continuous based on the fact that x is real, then turn around and say x is an integer, but the prior conclusion...

Still don't follow your logic. How does x = 3n imply that x or n are integers?

In this case x is an integer and hence our function is not continuous.

This function is not continuous so IVT doesn't apply.

For any \(\epsilon>0\)? :) I agree intuition says yes, but a proof/solution solidifies it.

Can you guarantee that at some point x = 3n, for every possible combination? Suppose my current ratio is 54 / (54 +92), how do you know that at some point x = 3n? Can I go from 74.81% to 75.62% without touching 75%? Turns out this was pretty trivial... Let x = success, y = failure. We're...

Of course it has a solution when x = 3n. But this is only sufficient, and not a necessary condition.

Turns out it's not the case. They all have equal probability. Coded it up too and I'm getting about 0.01.

Last number should be 4/6 ... in which case you don't have a contradiction, yet. I believe the answer is yes, you have to pass through 75%.

I got 1/100 using a binomial tree approach for the first question.

\(\frac{y_2-y_1}{x_2-x_1}\)? Am I missing something?

Write down the expectation for total distance covered, minimize this distance. You can either do it using angle as the parameter or distance walked to middle wall.

Look up Benford's Law, the answer is 1. You can reason this out as well without knowing this law.

I think I'm missing a couple pieces from your logic. I assume we stop when we roll > E if E is non-integer, so I think your floors should be ceils. Also for (\frac{\lfloor E \rfloor +100}{2}), shouldn't this represent (E(winnings - rolls | roll > E))? I think you've only got a piece of that...

Search the earlier pages in this thread. The point is just because someone writes down something, doesn't mean it's solvable, and if solved (especially something "infinite" or with limits), the solution isn't guaranteed to be the correct one. In particular for this problem you can prove which...

Got 30 using trig, stuck on the geometric solution...

Unfortunately this offers no long term potential gains. So it's a one time payment, and it could potentially be lucrative if I get enough people to buy. Now "lucrative" is a relative term, and getting anyone interested in any particular product on the site, or the rewards, are totally different...

Berkeley''s MFE program tends to focus on Matlab so I don't know how well or how they structure their C++ course. Baruch focuses more on C++ so their program will likely be more in tune to what's needed. Baruch's course is also taught by Daniel Duffy, a respected and well known name in...

Note that E(i) = E(j) =E for any i, j, rearrange and you have what I wrote.

I stand corrected, trying to think of a smart way to approach this.

Think of generating IDs for each person. Since each person must have at least one language the other doesn't know and vice versa, this amounts to generating 70 distinct IDs with 0s and 1s in each slot representing knowledge of a language or not. What is the smallest length of the ID? 2^n - 1 >=...

Easier way, let E be the number of rolls required until you get a multiple of n. Then E = 1/n + (n-1)/n*(E+1) hence E = n.

I think there may be a problem with 2 sets of numbers giving the same product e.g. 3*4 = 2*6. If you can prove that this doesn't happen for large n then you have the correct solution. I'm not entirely convinced that it does happen though ...

In all honesty it depends on what kind of work you'll be doing. Matlab a more of a niche-filling language, whereas C++ is more global. Given the choice I would go with C++. Have a look at job postings that may interest you now and in the future. You'll likely see that C++ is more sought after.

Just to make your post clear, I think by statements you actually meant definitions. Not every statement is an iff.

Of course it's possible. How well it works is a different story. Which options are you using to hedge? Index, single name? How well does your portfolio track the index. What is the tradeoff between return secured vs. premium payed? Buying puts is a little better than selling calls (higher...

I think prime power implies a positive exponent, which is why 1 may be excluded from some definitions.

Total derivative Leibniz rule. Should be straightforward. See http://en.wikipedia.org/wiki/Leibniz_integral_rule

FYI the link is broken.

Stich your curve together using some interpolation scheme. The simplest is piecewise constant or piecewise linear. Of course this is not really what is used in practice, one may want to use spline interpolation instead.

Rewrite the option as: (S_T-(1+\alpha) \min(S_t) = S_T -\min(S_t) -\alpha \min(S_t) +\alpha S_T - \alpha S_T) (\Rightarrow (1+\alpha)(S_T-\min(S_t)) -\alpha S_T). Pricing is then trivially a combination of weighted lookback and future contracts.

Any swap has a path dependent payoff. IR swaps, equity swaps, dividend swaps, skewness swaps ... and on and on. I'm sure there are some exotic options out there with those features too, cliquets come to mind.

How long was your backtest period? I belive I saw 60 days, that's hardly a backtest, and it's heavily dependent on market conditions over that period. Which equities were you trading? How were they selected? Did you incorporate transaction costs in your backtests? Slippage? What's the frequency...

Look up xlsread :) You can read from an excel file, specific sheet, specific range.

You can tex in windows just as well as any other OS, there are multiple editors available WinEdt, TeXnicCenter, TexWorks that comes with MikTeX.

Suggestion: Can we have an option to have an email sent to us when we have an alert?

Or Carr ....

The first will estimate the variance of S(t), which is not the usual sigma used in option pricing etc. The second method is what one uses to estimate sigma.

Did an American create this? Where's Africa? :D

Stanford makes more sense from a business perspective. Deciding which is a better Eng school Cornell or Stanford is really splitting hairs. Both are high caliber schools. Cornell already has a big presence in the city, Stanford does not. Stanford may entice some entrepreneurs from the west...

In terms of the most broadly applicable degree, I would think MS Stats would be your best bet. Statistical analysis is incredibly useful in a number of fields so you wont be restricted to just one area. MFE will almost certainly steer you towards finance. Finally, MS Applied Maths might not take...

There is no cookie cutter answer to your question. YMMV depending on where you end up (company/location/continent), what role you play in the team, how evolved / developed the team is etc, etc. Obviously the less critical your role, the less time you'll spend on the job.

They were an MS Finance student with a concentration in FE, not quite the same as an MFE. Take a look at the coursework required. Doing an MFE after an MS finance isn't really overkill. Doing an MFE after an MFE is.

Haha touche.

http://www.businessweek.com/news/2011-10-05/harvard-loses-top-world-university-ranking-to-caltech-on-funding.html Nicely done Caltech!

How about we put the elephant on skates, push him with a known force, and measure his acceleration?

Don't we need the density of the elephant to use Archimedes' principle?

Hahaha this is awesome.

I believe it depends on what your future plans are. If you are applying for a full time position and are willing to do the MFE part time, then put it in your resume, and mention the part-time. If it's for an internship, I think you should add it regardless. However, if you plan on leaving the...

It's a compounding effect I believe. Quantnet has drastically increased it's presence everywhere both online and offline. In addition to that, all the people that knew about the 2009 rankings, and have found out about them since, have spread the word and came back for the 2011 rankings.

nesense: I was merely pointing out the fallacy in your blanket statement. Baruch is in fact ranked and placed by many entities. Now you're fixated on one particular ranking that you don't find "good enough". Would you like to further modify and clarify your statement? I suggest a simple google...

The funny thing is, if a Haravrd alum published a ranking with Harvard in the top, no one would think twice about it. But because a smaller and obviously lesser-known school has a program that outranks (possibly) some of the Ivys etc, a lot of people are up in arms. Sure there are valid...

See a more complete and detailed list on wikipedia.

Perhaps the schools value Andy's honesty and integrity, and although they didn't participate in this ranking, he may very well likely have other interactions with them that require his discretion. Thus, him keeping quiet about who said what allows his to keep his relationship with the programs...

Andy, did you look at how the 2011 rankings would compare using 2009's methodology? Also how would the rankings change had you included 2009's methodology in 2011's methodology? Easily done by assigning a simple weight to each methodology.

Emalu, doesn't every ranking have doubtable data accuracy? Andy "heard it from the horse's mouth", it can't be that skewed can it? Would you like him to produce sworn testimonies and/or notarized statements? Subjective weighting? I didn't realize there was a universal standard to conducting...

No response to inquiries sent out to amass data for rankings?

How different would financing euro debt be versus financing drachma debt? I'm not clear on this, but wouldn't the same people who would finance them in drachmas finance them in euros? Also I feel that leaving the euro would cause a bigger panic and possibly more defaults. There would be bank...

Seems like Greece said they plan on staying in the Euro and Merkel's party said the same. The only person hinting at Greece leaving the Euro was Canada's finance minister. Default is imminent, leaving the Euro is not.

You mean dead? Surely it's not that dire. I believe in the 11th hour the ceiling will be raised, people will just not chance the shaky economy's "recovery". The real question is what kind of deal will they make? Will it be substantial (doubtful) or will they just kick the can down the road...

Could it be because HY products are already known to be junk, whereas IG products aren't? As such, they (IG) are more susceptible to and overreact towards downgrades/price movements etc.

Offtopic: It seems like the point goes to Windows here on the Linux/Windows debate. :D

Bank Teller Doctor Engineer Postman Trader :D

This says nothing about the susceptibility of Unix machines to viruses. True most servers, databases etc are housed on Unix boxes, how many emails & websites are accessed on these boxes? How many different peripherals are plugged into these boxes? That's the difference. You don't usually use...

Macs and *nix machines are susceptible to viruses too. They haven't been targeted because there is no benefit in doing so. Spammers, DOSers etc see no use in attacking machines that make such a small percentage of online computers. Basically, the're superior in this sense because they're...

Vista was a POS when it came out. It was Windows 7 beta ... Still a Windows fan considering how many kinks have been ironed out. Everything is compatible (*nix/Mac have issues), software is abundant (again issues with *nix & Macs). Sure I have to reboot once every couple of weeks or so ... and I...

Common misconceptions about the p-value taken directly from Wikipedia (it's a good read for all): The p-value is not the probability that the null hypothesis is true. In fact, frequentist statistics does not, and cannot, attach probabilities to hypotheses. Comparison of Bayesian and classical...

1. What's the point of beta > 1? This tells me how it trends with the market, I guess this allows me to assume positive drift? Or not ... depending which way markets are headed. Anyway, based on markets today with positive drift and beta = 1 I expect it to be above $20. 2. Make some assumptions...

A product of Bernoulli (mean zero) random variables still has mean zero. Hence E(det(A)]=0. E[det(A)^2] = sum of entries with squares + sum of entries without squares. The 2nd half is zero, the first half is a sum of 1s, hence var[det(A)^2] = n! Actually ThisGuy's argument still holds, if you...

My stats are a little rusty, but I think you might want to run a t-test. Tests for differences in means under various assumptions of population size and variance.

Bring it to NYC!

It's harder to go back to school once you're fully employed and have a family, etc. So if CMU is something you really want, and think that in the future you'll want to go back to school, maybe it's best to do it now. After all, you'll be working your whole life. If you got the job now, maybe...

Most (all?) science PhDs are funded. Math usually not as much but still funded. That is odd that Stony Brook is tight on funds.

Yes, two practitioners. The course title pretty much draws the distinction: 1st Half: Time Series Analysis 2nd Half: Algo Trading

It started off not far from there. How many students were actually enrolled I don't know. The first half of the course was interesting and likely useful, however given that I've seen Laplace & Fourier transforms and Complex Analysis before I benefited less from the first half. The second half is...

FORTRAN is huge in physics, especially particle physics. Cornell's particle accelerator team uses it, a lot of CERN's legacy code is FORTRAN although I believe some newer stuff is being ported/written in C++/C. It's mostly a physicists language as far as my experiences go.

Can you give an example where C-syntax is more convenient than C++ syntax? I definitely agree, but the ease and clarity of code from the C++ viewpoint makes the C solution "ugly". If you're doing this for solely your purposes and your own code, then that's fine. If I have to read your code, work...

Can you elaborate on both points? Given that n>2 then P(sum previous n-2 rolls is even) = 1/2 isn't it? Also I'm missing how the probabilities are not independent/conditional?

I realize that my P(even) = 7/12 > .5 I'm curious to know where my logic fails. Doing this using infinite series: Let \(E_n\) = Match at nth roll and sum is even, and \(N_{n-1}\) = No match at roll n-1. \(P(Even) = P(E_2) + P(E_3 \& N_2) + P(E_4 \& N_3) + ...\) Now \(P(E_n \& N_{n-1}) =\)...

Nicely done Peter. Now anyone know why my argument above doesn't work?

Actually I made an awesome mistake here, P(even) = P(rolling the same number in 1st 2 rolls) + P(even | 1st two rolls are different) = 1/6 + 5/6*1/2 = 7/12. P(odd) = 5/12.

Primus can you show some details to the calculations?

Good point ... Back to the drawing board. I guess you can just separate out the case where n=2 and then get P(even) = P(rolling the same number in 1st 2 rolls) + P(even | 1st two rolls are different) = 1/36 + 1/2*(35/36) = 37/ 72, whereas P(odd) = 35/72

The last two rolls don't matter as their sum is even, so whatever the sum was before that, it will retain it's parity. Hence we're only looking for the probability of a sum of random dice rolls being odd or even. 1/2

Misread the problem, assumed flipped meant the same as flips it over :D So yes it's not symmetric and Bob's solution is correct. Write down the transition matrix and find the eigenvector corressponding to eigenvalue of 1.

The problem is symmetric in regards to heads vs tails, so it should be 1/2

What's sad is that I thought to myself this weekend, "What's the date on Monday? 3/14 ... oh that's Pi Day!"

They are not identically distributed Tsotne. I think this is more of a number/theoretical exercise than a real application. This is just a simple integral that needs to be computed.

Ahh OK that's different. Didn't know you were implying that. Seems that the problem can then be simplified a little. Recall B_t - B_s ~ N(0,t-s). Try to work it from there.

Assuming B1, B2 and B3 are iid BM, you should be able to answer this by appealing to symmetry. P(B1<B2<B3) = P(B1<B3<B2) = ... Six such permutations, hence the answer is 1/6.

Yeah, I wish I had 3 million laying around too ...

I think that sums to 4, not 3.

Personally, I haven't tried it so I don't know. But 15 seconds for a general matrix seems really fast. Why are you inverting matrices anyway? People tend to shy away from that.

I guess that all depends on what type of matrix you are talking about and how you can store it. Essentially your limits would be available RAM and/or available HDD space :D

I'm surprised this hasn't gotten any comments or publicity. I'm sure people are arguing on either side of it's merits and drawbacks. Does anyone think it'll be as popular as the VIX?

Yes, those limits are correct. In general the limits are the domain of the random variable. Look up the Cauchy distribution and you'll see.

Umm, take it's pdf and compute E[X]. Where's the problem?

May 21, 2011

Something along the lines of a hacksaw and a blender comes to mind. Also they never mentioned what fridge it was, so I can assume we're dealing with a walk in cooler. Hence, I'll just lead the giraffe in with some carrots(?) (what do giraffes like to eat? Apples?)

I think the OP was looking for an closed form solution to the sin(t)e^(stuff) integral. I don't think you're going to find a closed form solution to this.

I totally agree. It seems illogical to think that things must get worse before they get better, but in some cases this works out. Think about a business going under - sure they need to cut spending - but maybe temporarily boosting their advertising/R&D/whatever budget gives them the boost they...

Sure people will have opinions on whether it will work or not. But was it a bad idea from the onset, or is it a bad idea in hindsight? There's a huge difference there and calling something a bad idea after it fails, when everyone agreed with it from the beginning, means nothing. Good ideas will...

No it's not very encouraging if everything plays out as described. I'm curious to know what the alternatives are? All Bernanke is trying to do is stimulate the economy and restore confidence. Keeping rates low is a good decision in my opinion. QE2 I'll leave up for debate. What's the...

Do you mean the pricing model for FX options? I've seen this question before. Is there a good answer to it?

Peter's answer seems correct. I think my answer solves the problem of exactly one 10 and one 11 before a 7 :)

Sure you can use an infinite series to solve this. I think my method gets around this by only considering what is needed. Ie taking a smaller sample space in which I only need 10, 11 and 7. Here's the solution with AND and using infinite series: Count the numbers of ways to win: Clearly you...

I think I've answered it as an AND problem. No?

Rolling a 10: 3 ways, an 11: 2 ways and a 7: 6 ways, for a total of 11 outcomes. Hence need either a 10 or an 11 for the 1st successful roll (could be after many rolls), then the other number for the 2nd successful roll, all before we get a 7. So P(10 and 11 before 7) = P(10 or 11 before...

Is there a better way to get 2010^8? Without my logic? Too lazy to think ...

The 16 factors of 2010 come from the 4 prime factors of 2010, 2, 3, 5, and 67. To get the other 12 factors we group the prime factors. 2 can be grouped 8 different ways, ie it shows up 8 times within the 16 factors, hence so do all the other prime factors. So when we take the product of all 16...

Doesn't sinh blow up at infinity? In which case neither of the sin functions tend to zero, hence the integral can't converge.

Are you looking for free, almost free or "free"? Personally I prefer either Maple or Mathematica.

That has to be one of the stupidest moves ever in my humble opinion. Are people really going to want to tote their phone and cord with them to be able to access their PIM data? Pickup the Playbook in your house and head to the TV room, kitchen and bedroom to check email, BBM etc, and each time...

About time. Now I wont have to worry so much about dropped calls - who really "talks" on the phone any more? - and limited bandwidth with my iPhone on AT&T ;) Btw I'm on a jailbroken iPhone.

Another way for sqrt(0.1) = sqrt(10)/10. Still need to approx sqrt(10). It's close to sqrt(9) = 3. How close? We can guess or make some argument about where 10 lies in comparison to 9 and 16 so we know how far sqrt(10) lies between 3 and 4.Guess less than 3.2 more than 3.1 so, 3.15?

Got 6 meters for 5, but I used Taylor series expansions. Are those taught in high school? I had an AP student that was taught Taylor series.

Awesome Andy! Time to stop working and start doing brainteasers ;)

A great question for debate possibly ;)

Yes I was pairing up the combinations and not looking at their sum :-\" I don't think the marbles are distinct though, so counting permutations doesn't make sense. Dunno ... bad question. Actually come to think of it. For even sets: Picking an even number of objects creates a new even set...

That is true if you use the same number of terms on each side. Also we're not given the option of drawing 0 marbles. If we were given that option, then for an even number, say 4, we could draw 0, 2 or 4 as even sets but only 1 or 3 for odd sets. Thus the question is reversed, but remains the...

Nice now I want that laptop too! Love the iPhone and iPad, but hate Macs ...

Round covers are easy to place on the hole. They also can't fall through the hole like a square cover might. Pencil in a blender: You might be able to just reach up and climb out, or rock and tip the container over?

Why non-apple? I'd take an iPad, although the newer version please.

Indeed, I was thinking top 5 from your comment above, whereas Peter answered for top 3.

I don't think this works. Race 1 may have all the top 5 horses already competing. However, you only consider the 2nd and 3rd place horses of this race.

Take Calc III and the Probability course, they're both more applicable and valuable to an Quant program. If you have time Advanced Calculus may be nice, if you're interested in doing and understanding research.

Of those courses, the ones that sound most promising and are more closely related to financial engineering, are the last two. Complex Analysis and Modern Algebra are pretty far off the beaten path. Analysis will be good and possibly PDEs, although I don't know what the course covers.

Who, who, who codes like this? Example: const double One2Pt20462262185th = 1.0/2.20462262185;

Not unless T-t < 1.

That is correct, that is why I'm wondering if Kr is correct, and if it shouldn't be Kr(T-t) or something to that effect.

Google is your friend, my friend. You have everything you need in your statement, just look up Put-Call parity and digest. Or think up a way to exhibit arbitrage from what you're given. Just from a quick look is this correct C - P > Kr?

An update, yesterday the the Senate Dems voted to pull the measure from consideration

PT is mainly for people with a day job, regardless of the field. Working FT and doing any FT program is extremely demanding which is why PT exists. For Baruch I know you can chose either and I don't believe your application is judged any differently whether you want to be FT or PT.

Clearly you're both correct

Seems like you've answered the question yourself. If you're this torn and leaning towards quant before you even start your PhD, it'll only get harder to stay focused whilst trying to complete your PhD. Follow the path of least resistance ;) What motivates you more and gives you more pleasure...

Yes, I wasn't thinking clearly, you are correct, edited my post above. I think Google may provide you with some answers in regards to proofs and bounds.

Are you looking for an actual proof or intuition? Basically, you're discretizing your model, which means you're only approximating it within a certain degree of accuracy. Because of this you do introduce errors, in this case negative values. Also take a look at the discretizations, the way...

The actual model doesn't go negative, but the simulation may. You're approximating the evolution of the stock price. If you're stressing your approximation, ie large time steps and large vol, you're going to get negative S.

Your stock process is a Brownian motion with drift. S goes up on average. Hence the longer the TTM the more expensive the call is (the call has more time to expire ITM) and the less expensive the put is (the put has more time to expire OTM).

What exactly are you looking for? You can skew the normal distribution, and even add kurtosis if needed. You can pick a different distribution to work with as well, Student's t and any other power law distributions all have fatter tails which may work depending on your data.

An internship isn't a must to get into a good program, neither is graduating from a well known school. Showing that you're prepared, committed and motivated is a lot more important. Graduate with a good GPA, do well on the GRE, have the prerequisite background, and have a good statement of...

Get experience in the finance and programming areas :) Seriously if you can, take a couple programming courses, C++ is a must. Learn some VBA on the side. Maybe take a finance course or study some standard textbook on the side. As a math major, take the courses that will best prepare you for an...

I reduced it to half after adjusting for the questionable prices, and some fictitious costs. And yes you are only limited by the options being sold. Have you seen the volume and open interest for the ones you mentioned? Barely any. I'm sure you could shorten your time horizon. But there's still...

I have no idea whether anyone has actually used this strategy, but here are a couple thoughts: 1) Why use the mid for prices? You can't guarantee that price, you might as well have used the most profitable price. 2) Capital gains, fees, costs may eat a lot more of your small profit than you...

It never appears to save the preference on my end. That would be nice. Also just to bring this up again in the appropriate place. I would like to see a "Quantitative Interview questions/answers" section. I understand your point of wanting critical mass before the section is created, but I...

:)

Did anyone attend this last year? I'd be interested in any feedback.

I think by definition a Black Swan event is a tail event. Their frequency of occurrence and the capitalization on them is a different story though.

This is laughable. I'd be interested to hear their motives for doing this. Do they think anyone will listen? Are they trying to prove a point (that they're a little delusional)? Of course we knew they'd disagree with the awarding, he is a criminal in their country. And how exactly does this...

The distribution of final stock prices will look very different for different vols. Think of N(0,1) vs N(0,10). So yes you may hit the same final stock price, but the frequency of the hit (or the chance you'll hit it) is very different and hence determines different prices too.

I don't think Goedel's incompleteness theorems have much to do with reducing mathematics to simple first principles. Proving something is true, and proving mathematics is complete are what Goedel's theorems relate to. However taking existing maths, which is correct, we can reduce it to simple...

It's true you can break down pretty much any maths and have a computer do it in simple steps, that includes proofs. But the amount of work needed grows, let's say, exponentially at the maths gets harder. You have to work really hard to break everything down into the basic operations and comparisons.

It is a direct translation of what we say in Greek too. Take usually means to possess physically in Greek, so we don't take exams, we sit down and "write exams", i.e. fill them out ;) And after the exam, we ask each other "Did you write?", as in "Did you fill everything out (do well)?"

You're running a simulation for a particular option it seems, hence it would make sense to use the strike of the option, K, to get your LV.

Actually euroazn, I think he's only talking about the "vector" part of multi-variable calculus, which deals with divergence, curl, surface and line integrals, Green's and Stokes' theorems, etc. Most (if not all) of those concepts are not used as far as I know by quants. Multivariable calc is...

About 14.7, nice problem.

The only redundancy is either 1) All securities are multiples of each other or 2) the securities are not (decently) uncorrelated.

I think you're running into trouble with (decently) uncorrelated (written as ~ for brevity). If I understand you correctly, a set that satisfies ~ means that every security satisfies ~ with respect to the remaining securities. I.e. every security can be written as a linear combination (lc)of the...

There has to be a more elegant way to prove this than to brute force your way through this many starting configurations, even with the groupings. What are they going to do for the 4x4 and the 5x5 cubes?

That's exactly why I was saying it would be neat. Proving something you know to be true has it's own merits. But having to rethink everything you know because it's been disproven, now that's a radical shacking up. Deep down though I do believe P!=NP ...

It would've been been great if P = NP :D

Actually those types of problems are often recast into abstract algebra problems. So while abs. algebra doesn't deal exclusively with these "geometry" problems, it is used to solve them, rather nicely. MFwhartonite, if your real analysis course touches open measure theory, then I'd say go for...

Chrome. Fast and that's all I need :)

Can't we just create a subsection of the forum to host brainteasers? This way each problem can get its own thread, and all responses therein will pertain to the original problem. It'll be a lot more organized and easier for people to contribute to a solution, talk about a problem, before it gets...

Goat eyes, tongue, brain, intestines, kidneys, hearts, livers, testicles ... And the list goes on. All on Greek Easter. I only consume a few of those really.

Crocodile. Flaky like fish :)

How can 232792560 be divisible by 11^2 when you only have one 11 in its prime factorization? The answer is still 232792560 :)

Answer for 5 is 232792560.

BBW you raise valid points. I haven't read the any parts of the bill, only what I could gather from websites. The public was already tiring of the debates on this bill, I doubt they would even consider or care to hear about a single payer health care system. All the questions you ask...

So what's the alternative? Leave those who can't afford health insurance out, because 250K+ earning individuals can't afford a little extra taxes? In the end this is going to bring the deficit down. This is not a bad thing. We're expanding healthcare to include people that weren't eligible...

1) Fib numbers have a closed form. 2) Every 3rd fib number starting from fib(0) = 0 is even, (i.e. 0, 1, 1, 2, 3, 5, 8 etc) So: int fib(int n); void main(){ int sum=0; int n=0; while(fib(n) < 4000000){ sum+=fib(n); n+=3; } cout<<sum<<endl; } int fib(int n){ double f =...

What vol book Andy?

A windows based macbook?

You're counting the last case twice, which you shouldn't. Its only once that the money is behind door #3, not twice. It doesn't matter which door the host opens.

Lookup the Cauchy distribution :) (Edit: True is expectation is undefined, not infinite #-o)

BBW, I agree! Too bad most of that isn't touched upon in an undergraduate linear algebra course. I would have to say algebra in general was one of my favorites, and algebraic topology and maybe complex analysis, and probability. Ok, I was a math major, would you expect me to only have one as a...

Indeed, I stand corrected.

Last I checked (\frac{1}{\sqrt{2}} = \sqrt{2} \cdot .5). So answer (a) is correct. (b) and (c) are not the same as (a).

Ok we've officially high-jacked this thread. Bbw you can argue your point for any math subject, they usually always have a common overlap somewhere. And it also depends on what you're focused on in alg. geom. All I was saying is that real analysis is not essential in general, it depends on...

There are schools that don't require analysis for even math undergrad. Even for your PhD you can avoid taking analysis.

Exactly my point chaoticcrambler. Its not needed for algebraic geometry, algebra, logic, etc, etc. I was just merely making the point that real analysis is not essential for any PhD, even one in mathematics, and that such generalizations aren't true. Sure, if you decide to do a PhD in...

New laptop, Andy. (But there's also the not so legal legal copies which can be had for those inclined, if you know what stone to overturn.)

For (3) this is a sequence of "perfect numbers", numbers which are the sum of their divisors. For (4) a finite number of particles can occupy a finite, and even an infinite amount of space. There's nothing about having a computer this fast the restricts either case. That leaves (c) or (d). (d)...

PhDs in what? Real analysis is only a biggy if you use it in your field. There are many more fields that don't rely on real analysis, or use it sparingly.

I think I will. I was sold by the snap to edge feature, which makes tex and its result a lot easier to manage ;) Of course I get a free upgrade so why wouldn't I? Although I think I may wait a month or two to have people work out the kinks, updates etc.

It is often those theoretical papers, which will 50 years down the line solve some of the most interesting and deep problems we'll be encountering.

Here are some suggestions: Linear Algebra, Probability, anything Numerical (Optimization, Linear Algebra, PDEs etc), PDEs. Advanced Probability with stochastic processes wont hurt if you can get up there. Most of these you'll see again in some form in an MFE program, but it wont hurt you. And...

Happy B'day mate!

Ummm ... google ;)

Either they weren't the best, or they got complacent, or they are/were just "lucky". I think its a combination of all three.

For those of you that do have facebook and are in need of a cheap meal (actually free): What’s the Value of a Facebook Friend? About 37 Cents - Bits Blog - NYTimes.com

There is no closed form for this sequence. Where did you find the question? Anyone with an answer has (dis)proved a good theorem.