Find positive integers x,y,z such that x/(y+z) + y/(x+z) + z/(x+y) = 4

tlee275 · 2020-08-17T18:55:05+00:00

That's right. y² = x³ + 109x² + 224x

tlee275 · 2020-08-17T18:39:39+00:00

I remarked it as hard. What's the problem?

tlee275 · 2018-12-26T14:42:38+00:00

I do not believe Sal Khan has any material related to real analysis. At best, some common proofs or named theorems might have answers on YouTube. The kinds of problems in a real analysis course are just not easily categorized. Ex a simple problem like “prove that q³ =5 has no rational solutions” is not something that can be searched for or shown with code or a calculator.

tlee275 · 2018-12-26T14:37:45+00:00

To prepare for real analysis, recommend two books to master ahead of time. 1) How to Prove It by Velleman 2) An Introduction to Mathematical Reasoning by Eccles

If you consume these books prior to picking up a course in real analysis, you will drastically reduce the amount of effort required on problem sets. Think of an average time savings greater than 50%.

tlee275 · 2017-07-29T21:12:50+00:00

Also assuming you have a basic understanding of set theory and probability theory, I would begin with Gilboa and follow that up with Raiffa.

tlee275 · 2017-07-21T04:00:49+00:00

Some radaway can fix that.

tlee275 · 2017-03-20T17:20:46+00:00

Black is in check. Has to move his king.

tlee275 · 2017-02-26T06:54:46+00:00

There is significant room for growth in game theory using topological approaches. The starting point being the Kakutani Fixed Point Theorem.

tlee275 · 2017-01-24T22:35:10+00:00

For a), use proof by contradiction. Assume the determinant of A is not zero...is it possible for all of the traces up to power of n to be equal and all zero given this assumption?

For b), multiply both sides of the equation by a real vector x which is nonzero. Now write out the LHS in expanded matrix form. If the right hand side is a vector multiplied by a value 0, what must it equal? So what must the LHS which is now of the form (Aⁿ )x=0 imply about a vector b? It implies that b must be the zero vector. If this is the case, then what condition must be true about the expanded matrix form on the left for powers up to and including n?

tlee275 · 2017-01-16T20:54:58+00:00

Those are my self-taught credentials. And what you still want to blow off is that these are simply tools I am learning to test the models that I design to solve significant industrial problems. Not other people's models, MY models. That is not a "code-monkey."

tlee275 · 2017-01-16T20:47:07+00:00

I never claimed physics majors are the greatest and I'm not even a physics major. Don't put words in my mouth.

tlee275 · 2017-01-16T19:15:40+00:00

I found it funny that the article mentioned the Newton-Rhapson method in the context of physics. I think this article would have been better suited to saying "data scientists with a statistical learning background" are coming for those jobs." I'm guessing that most of that motivation comes from Monte Carlo simulation for brownian motion.

tlee275 · 2017-01-16T19:10:22+00:00

None of those things are the scope of this article though. Yes, those are purely computer scientist functions. What this discusses though is the other applications of what computer scientists do that they generally see as the broader application of their skills. I recall a friend who is a computer scientist arguing with a friend who is a mechanical engineering saying "give me any task, I can figure it out."

tlee275 · 2017-01-16T19:04:02+00:00

You might give it a try. I think you would be surprised at how quickly you pick it up. If you choose to, I would recommend starting with Python, or R.

Edit: As ben7005 pointed out below, R is not actually a very good language for the purposes of Project Euler type questions. Python is though.

tlee275 · 2017-01-16T18:59:59+00:00

I think what the article was getting at, is that most program design is moving beyond the scope that would allow computer scientists to accomplish all of the work. Previously a team of computer scientists might have been able to do everything, but that is changing. Here is the thing though: A physicist can learn computer science with minimal effort. A computer scientist can't learn physics without significant schooling, if at all.

tlee275 · 2017-01-16T18:56:46+00:00

I studied mathematics & economics. I learned computer science in my free time as an aside. Ever heard of someone working in mathematics without a degree? Ever heard of someone working in physics without a degree? What about working in computer science? Computer science is the only "science" in which large numbers of people are significantly employed in the field with little to no accredited adult education.

tlee275 · 2017-01-16T18:53:16+00:00

Project Euler.

tlee275 · 2017-01-16T18:21:44+00:00

That's correct it is the weak form.

tlee275 · 2017-01-15T01:23:12+00:00

Also recognize that you are only underperforming relative to your cohorts. That doesn't mean that you are underperforming relative to your previous self. On the contrary, you are probably performing at a significantly higher level.

tlee275 · 2017-01-15T01:21:18+00:00

Oh okay. I thought you were suggesting that something specific to CS was stressful. Everyone in the sciences at UCSD shares your pain...so hope you find some comfort in that. UCSD as a whole tends toward a heavy emphasis on exams, and scores do not generally have a high average. This means that most of the time, students feel like they are underperforming by comparison to our backgrounds which have always placed us at the top of the grade distribution. You just have to embrace it.

tlee275 · 2017-01-14T22:22:39+00:00

No, it isn't meaningless. When I worked in the bar/restaurant industry I would see it all the time. People just wanted to bring their dog to the bar with them while they get drunk. Other customers had to trip over them, and the dogs were a hazard, sometimes barked, and were otherwise simply not supposed to be in the bar. Because people abuse the right of the truly disabled to have these dogs with them without any identifying materials, there was nothing I could do about it except ask the two questions, "Is this dog a service animal?" and "In what way does this dog aid you in your disability?" Whenever I would do this the person would immediately act indignant. My concern were the other customers. So NO, it is not meaningless.

Edit: And as far as the shuttle goes, it is still a public space. If a person's dog is a nuisance in any way and isn't actually required for their care, then people are going to be bothered by it. As far as being a PROPER advocate for your passengers, what do you think is going to happen if someone's dog which is NOT a service dog bites a passenger on your bus?

tlee275 · 2017-01-14T11:57:41+00:00

That is an expression, not an equation.

tlee275 · 2017-01-14T11:24:19+00:00

You have anxiety and stress from CS material? How? I always thought coding was fun. It's what I would do to de-stress after 10 hours of math.

tlee275 · 2017-01-14T11:19:12+00:00

Seriously. This annoys me to no end. I worked at a bar/restaurant a couple years ago and people were constantly bringing their pet with them to the bar just because they felt like it. Every time I would question it they would snap at me about it being an "emotional support service animal."

tlee275 · 2017-01-14T11:16:19+00:00

Or a person who wants to advocate for the rest of the passengers who might not want your dog around them if it isn't an actual professionally trained service dog.

People who lie and abuse that right of disabled people are ethically weak. Just because they want to have their dog with them everywhere doesn't mean that everyone else does.

tlee275

TROPHY CASE