Recent content by dzogi

I think I sorted this out. We're taking \delta<1, so it doesn't matter since we only have to find one \delta to prove that the limit holds.

I'm trying to understand \epsilon-\delta proofs, but I'm having some trouble. For example, if we want to prove that \lim_{x\rightarrow2}x^3=8, starting from |x^3-8| we get to something like |x-2||x^2+2x+4| And this is what confuses me: we conjecture that |x-2|<1, then |x|<3, so we get...

You might be interested in Linear Algebra Done Right, Axler.

Billygoat, thanks for the answer. I was very confused about this mineral, as a local (as in, Macedonian) newspaper wrote that it can release large amounts of energy, thus becoming an "artificial Sun", which sounded like and seems to be - nonsense.

I came across various sites that discuss the mineral known as lorandite (TlAsS2). One, a more 'popular science' one is www@worldpress.org/Europe/2781.cfm . There's a paper too, but I can't get it since it's not freely available...

If I'm not mistaken, that's the energy of just one particle from the spring.

Yes, it was a mistype :)

Donal Duck is measuring the proper time interval t_0, so the interval measured by Drake is t=t_o\lambda. We're given that t=2t_o. Dividing both equations we get that \lambda=(1-\frac{v^2}{c^2})^{-1/2}=2. Solving the equation yields the solution.

[SIZE="3"]1. First Problem Homework Statement A disc with mass of 50kg and radius of 20cm is rotating with a frequency of 480rpm, and after 50 seconds, as a result of the force of friction, it stops. What's the moment (momentum of force, torque) if during the rotation the disc made 200...

a) s=\frac{1}{2}at^{2}; v=at b) at the end of the 4 seconds period, the rocket will have velocity of v (calculated above) and a downward negative acceleration of g=-9.81m/s^{2}. Do the rest yourself :) Hint: You can also use the law of conversion of energy for the second part.

So, since this is my first post on this forum I'd like to say hello to everyone. This year SAT-like exams are introduced in my school so I want to revise all the material from these 4 years of high-school education. I've tried Serway's book - it's nice, I can understand it completely, but I...