Recent content by DarthPickley

  1. D

    Topology question → What geometric figure?

    uh, I think when it says "he decided to move his fingers... felt something on his shoulders... turned around to see who had done this" (paraphrasing) that there was some sort of portal / wormhole in front of him, like the part in front is glued to the part behind him.
  2. D

    Law of Sines (Elliptic, Hyperbolic, Euclidean)

    Well, I created this thread (under Geometry/Topology) about the Law of Sines, specifically for the three kinds of geometries. http://en.wikipedia.org/wiki/Law_of_sines http://mathworld.wolfram.com/LawofSines.html The Law of Sines states that, for a triangle ABC with angles A, B, C, and...
  3. D

    I don't get why this troll physics is wrong.

    here is an analagous situation: take the function given by the limit as a --> 0+ of the function f(x) = a*sin(x/a). Clearly, this converges to the function F(x) = 0. However, suppose that this is like physics, so you are going to talk about the energy of the wave (no quantum stuff here though...
  4. D

    When will I learn about elliptical integrals

    Well, one thing I've been curious about is what would happen if a student who is learning about conic sections in precalculus just happened to ask what the circumference of an ellipse was. Now, I myself have too much of a history of asking questions that are revealing of my knowledge of higher...
  5. D

    Learning calculus over the summer

    well last summer before going into high school I just taught myself calculus and stuff, this year during school I'm not teaching myself the sort of stuff that I'm being taught, I'm teaching myself geometry stuff (my geometry class in middle school was boring... triangles are boring... I'd...
  6. D

    There is no set of all functions

    strange. it seems that it would be simple to have a set of all functions where a function is a collection of ordered pairs of an element of the domain and of the co-domain, so, given a set of which the domain and co-domain are subsets of, it should be simple to, for each element of the domain...
  7. D

    Medical Asperger's Syndrome: Myth or Reality?

    when I look into other people's eyes while they are talking to me, I become 'entranced' and highly distracted and cannot pay any attention to what the person is saying. Additionally, sometimes it causes me to spontaneously have a spasm or something, like I'll pass by a mirror and see my...
  8. D

    What is the Proof of the Pythagorean Theorem?

    do you mean the one supplied by Euclid in his Elements book? that one... its so impossible to understand without staring at it for a long time! Its kind of confusing. I don't really like it, mainly because it is one of the least intuitive proofs possible for a pretty simple theorem. on...
  9. D

    Solving Dynamical Systems with Polar Coordinates

    I thought I had probably made a mistake. but anyways I just learned about Feynman's lost lecture so I have another way of understanding the Kepler stuff, but anyways, I think that here, for my derivations, I will redo things: having a vector v such that |v| = r, and then you have v + dv, with...
  10. D

    Uncovering the Mystery of Euclid's Proof of Infinite Primes

    you have to prove that ( a*b + 1 ) is not divisible by a or b, and the same for like (a*b*c*d*e*f*g + 1) is not divisible by a,b,c,d,e,f,g. (and of course they are not equal to one) this is done really easily if you say that a*(...) ≡ 0 (mod a), then a*(...) + 1 ≡ 0+1 ≡ 1 (mod a). so if it is...
  11. D

    What is the Proof of the Pythagorean Theorem?

    Well, that one you mention isn't really a proof at all, it just sort of shows that it works for the case of a triangle with side lengths of 3, 4, and 5.
  12. D

    Closed Form Solution | Definition & Meaning

    I think it also means you can't have an integral or summation symbol of any sort, you have to have simple functions and algebraic operations and numbers. also, what would be a closed form of the roots of x^5 - x + 1 = 0 ? you can't get it by infinite process unless you define a recursive...
  13. D

    How Does This Equation Relate to Protein Structure Prediction?

    for some reason it reminds me of the definition of matrix multiplication...
  14. D

    What is the Proof of the Pythagorean Theorem?

    make a square. make another square inscribed in it, with its vertices on the edges of the square. label edge lengths that are congruent. now, look for shapes and areas and triangles and stuff. . ._b_____a__ . | . ./ .\ . . . | a| ./c. . c \ . | b . |/ . . . . . . \| . |\ . c. . c. /| b| ...
  15. D

    Solving Dynamical Systems with Polar Coordinates

    There are about 4 pages of this stuff in my english notebook... (my physics notebook was full) This is what I got: θ' = (xy' - yx')/r r' = (xx' + yy')/r of course its possible that I made a mistake. most of my work from then on dealt with trying to derive formulas for θ'' and r''...
Back
Top