Recent content by tmccullough

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    Graduate Do I Understand Parametric Equations for Lines and Planes Correctly?

    Both of those quantities are the minimum distance from the origin to the plane, meaning the distance from the origin to the plane traveling in the direction of the normal vector (actually times the length of the normal vector, which is typically chosen to be norm 1 for simplicity). To see...
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    Graduate ALL TITLE:Is k[x^2,x^3] a Dedekind domain?

    Dimension theory (krull dimension anyways) is very much a fundamental part of algebraic geometry, and that's where I first learned it. Polynomial rings (finite number of variables) over a field are very "homogeneous", so every maximal tower of ideals has the same length. This will then hold...
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    Graduate ALL TITLE:Is k[x^2,x^3] a Dedekind domain?

    Consider that k[x^2,x^3] = k[t,u]/(t^2-u^3). The polynomial t^2-u^3 is irreducible, so it's principle ideal is prime. Then, your ring is noetherian and dimension 1.
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    Integral with bisquare function

    Because it's calculus - an integral and all.
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    Graduate Solving Rational Dependence in Vector Spaces

    That's not modified at all, that is the argument. I didn't want to give everything away.
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    Graduate Solving Rational Dependence in Vector Spaces

    I think I understand the statement, but I'm not totally sure. I suppose that you mean what is the measure of the set of all vectors which are rationally dependent (if this is even measurable)? I've never heard of rationally dependent before... I think this is the answer: Suppose...
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    Graduate Is NH Always a Normal Subgroup of G When N and H Are Normal Subgroups?

    If H is the klein-4 group, and N = <g> where g\in A4\setminus H, then the product NH=A4 just based on index.
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    Why this point is not essential singular point

    Functions don't have a "limit" at a simple pole (like this one), they have aribitarily large norm. At poles, the values "wrap around" the complex plane at infinity, in other words, the function hits all complex numbers with arbitarily large norm. You always see a complex function going to the...
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    Graduate Is There a User-Friendly Program for Checking Radical Ideals in Polynomials?

    GargleBlast42, I presume that you are associated with a university. Most math departments (that I've seen) have magma available for free. It's awesome for this, and many other, symbolic algebra problems. If you continue with algebra, it's a really good tool to have at your disposal.
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    Inflection Points: How to Find Them and Why They Matter

    You can absolutely solve this by hand. First, follow mr. vodka's advice and apply long division, sp that you rewrite your function as ax + b + \frac{cx+d}{x^2+2x} I'm struggling to remember the name of the next step (partial fraction decomposition?), write it as ax+b + \frac{g}{x+2} +...
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    Undergrad Number of ways of expressing n as positive integers

    I assume that you mean S_n is the number of ways to express n as a sum of positive integers, where orders matters. Consider the different cases for the last integer in the sum, all of which are disjoint, since order matters. There are n different cases. Explicitly: if the last integer is...
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    Inequality Problem from Spivak's Calculus: Chapter 1, Problem 4, Subproblem XI

    Stated in a different way, \log_2(t) is an increasing function. Inequalities remain true if you apply an increasing function.
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    Python Python: Calculating the average of scores and separatign into letter grades

    There are a millions way to fiddle with the logic of this problem, so I will just edit what you have here to make it more python-like. The end result will still be an array of length 101, where counts[x] will be the number of times score x appeared, as well as the other desired quantities...
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    Finding the volume using double integrals

    Where did you get the function e^{x/y^2}? I'm confused a little by your latex formatting - use { and not ( for enclosing the things in the super/subscript. Are you sure that's the right function? If so, what you've shown in the post looks correct. Unfortunately, I don't think you're...
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    LaTeX Drawing Braid diagrams in Latex

    I'm pretty sure people that draw such things use xy-pic. I know why you ask about one that's not too much trouble :wink: