Recent content by TimNguyen

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    Parametrization of a circle on a sphere

    Oh, there should not be a [theta] in the trigonometric functions, but rather the value (s/r). Hence, the parametrization of a circle would be: (r*cos(s/r), r*sin(s/r), sqrt[R^2 - r^2]) Thanks for all the help!
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    Parametrization of a circle on a sphere

    Homework Statement Parametrize a circle of radius r on a sphere of radius R>r by arclength. Homework Equations Circle Equation: (cos [theta], sin[theta], 0) The Attempt at a Solution I don't know if the professor is tricking us, but isn't the parametrization just Circle...
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    I can't believe it's a yogurt store

    Is this place called "Yogurt Land"?
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    Q2 Help: Quantum Mechanics U=100v & U=10000v Wavelengths

    You're taking QM and have not taken Calculus I? How is that possible?
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    QB Throws Football: Speed, Angle, & Distance Needed to Catch

    What are the important equations for projectile motion? There should be two you should be using, one for the horizontal direction and one for the vertical.
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    What are the displacement vectors and directions of a hiker's route?

    Break all 3 vectors into x and y components. You could do this because you have the magnitude and direction of the vectors A and C.
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    Heeelp with this antiderivative (silly question prob.)

    I think the general form would aid you. Int(sin(kx),x) = -1/k cos(kx) + C Int(cos(kx),x) = 1/k sin(kx) + C where k is a constant Edit: Never mind, you're using substitution. For the problem you stated, you could replace the "4x" with "u", but you must also change the "dx" to some form of...
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    Is Every Point Mapped to Itself in a Continuous Function on ℝ²?

    Sorry about that. My math is extremely rusty since I started graduate school in physics.
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    Is Every Point Mapped to Itself in a Continuous Function on ℝ²?

    I'm not so sure about this but do we not know how the function maps irrational numbers, such as sqrt(2)?
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    Logical Equivalence of x <=> y and (x-->y) ^ ((~x)-->(~y))

    I'd just use a truth table. If you don't know what that is, then I don't think you belong in math.
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    Graduate DDCS: Understanding What it Measures

    Hello all, I was doing some reading on doubly differential cross-sections and was wondering what does this actually measure, in a physical sense. The way I see it, it looks like the differentiation of the incident angle of the scattering with respect to the reflected angle? Also, there's also...
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    MATLAB Finding Prime Numbers Up to N: A Scientific Approach

    How would I write a program that finds all the prime numbers that are less than or equal to a "user-supplied" integer N, implementing the fact that I should only be dividing N by all prime numbers less than sqrt(N)?
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    Homeomorphism of Rings: Proving Existence for Prime Numbers p and q

    Let p,q be two prime numbers. Prove that there exists a homeomorphism of rings such that f([1]_p)=[1]_q from Z_p[X] into Z_q[X] if and only if p=q. I believe that the converse of the statement is trivial but the implication seems to be obvious? I really don't know what there really is to...
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    Proving Group Isomorphism: Q& & Z[X]

    Thank you once again, I think I have a brief idea.
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    Proving Group Isomorphism: Q& & Z[X]

    So basically, all I need to do is for an arbitrary a,b in Q, then find a way to compute it so it will lead to: f(ab) = f(a) + f(b)?