Recent content by RJLiberator

I'd be interested in hearing how more people 'study' textbooks. In my experience, when I start a tough textbook I fail miserably after a few days. I read a chapter, do some problems, then almost immediately forget the knowledge. I'd love to hear more!

This is perfect. You don't want to go quiet and run the risk of being forgotten (we all know how busy professors are), but you also don't want to do what Vanadium 50 is suggesting (didja get it). By putting in that bit of effort to show more interests in the PHD advisors work, you are making...

Thanks for the reply. In my research, I learned how to use Linux systems and code in various languages (FORTRAN namely, C++). It's all on the theory side of things rather than experimental. It's been hard for me to get the 'mojo' or motivation to look into computer jobs since my coding skills...

I'm looking for suggestions on ways to: a) Make some money b) Get valuable experience that looks good on my grad school application My timeline: Right now it is September 2018. I will be taking the Physics GRE in September 2019/Oct. 2019. I'll be applying for Physics Grad Schools soon after...

Sorry, my teacher calls PMF and PDF the same thing while my book considers them differently, that is why I mix up the pdf/pmf language. So, are you saying the PMF looks like tossing a coin until it records a value of 1? Essentially it gets 0 or 1 and that means the average would be 1/2. But...

Homework Statement We have F(x) = ∑ (1/2)^j [Sum goes from j=1 to x] For the cdf F(x), find the pmf f(x), the 25th percentile, and the 60th percentile.Homework EquationsThe Attempt at a Solution I've been doing numerous of these for continuous distributions, however this one is tricking up...

Perfect, thank you much for the confirmation. I just didn't want it to end up being a trick question considering all three parts have the same answer. So the question just wanted to clarify discrete vs. continuous after all. Cheers.

Homework Statement Let P_{x}(x) = \frac{x}{15}, x = 1,2,3,4,5 ; 0 elsewhere be the pmf of X. Find P(X=1 or 2), P(1/2 < X < 5/2), P(1 ≤X≤2). Homework EquationsThe Attempt at a Solution I believe what this problem is trying to show is the difference between discrete and continuous Pmf...

AH, so I was on to it when the range is a function 2x^2, but inputting the domain into this function results in x(-1) = 2 and x(1) = 2 thus the upper and lower limits = 2 and the integral is equal to zero. Nice!

Sorry guys, I am having a troubling time understanding this problem still. The problem is due (and i'll have the solution) in about an hour. So, I'm just going to try once more here then if I get the solution I'll post the proper answer here. So, we know the domain is from -1 to 1. The range is...

Since x must equal y and it's from -1 to 1 we have a line as you described. We'd do the integral from -1 to 1 of 2x^2 and get 4/3, correct? Although we need an area here. Under this logic, would it be 0?

Hm I do not think that they both have the same interval for boundaries. This is part of a 3 part question and it is part 2. Part 1 actually has the same set up with -1 ≤ x ≤1, -1 ≤ y ≤ 1. That would mean part 2 has to have x = y otherwise they are the same question. For part 1 I did end up...

Homework Statement For every two-dimensional set C contained in R^2 for which the integral exists, let ##Q(C) = \int \int_C (x^2+y^2) dxdy##. If ## C_1 = [{(x,y) : -1 ≤ x = y ≤ 1}], ## find Q(c).Homework EquationsThe Attempt at a Solution This was a tougher one for me (the other 2 on this...

Hm. I think I was making this harder then I needed to make it: C' = {(x,y) : x^2+y^2 ≥ 2 and |x|+|y| ≤ 2 } This seems to get the correct area.

Thanks for your help. For part 1, I understand now and see why I was confused. Now I understand that I have the correct answer. For part 2, after thinking about it, I also understand why my area-area part did not work out. It's more to say: (|x|+|y| ≤ 2) - (x^2+y^2 < 2) = the complement, but...