Recent content by pbandjay

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    Undergrad What's the difference between complex numbers and vectors?

    The gist of it is that the complex numbers form a field (just like the reals), so are equipped with the same properties as the reals (associative, commutative, closure under an addition and a multiplication, existence of identities w.r.t. the operations, inverses, distributive). A vector space...
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    Will I Like Dexter? My First Experience with the Show

    I was never able to watch the saw movies very well either, but Dexter is my favorite show! Even right away in season one, the plot is amazing. My favorite seasons are one and two, personally. But a lot of my friends liked season four the most. They're all good.
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    High School Is 495.5 Equal to 495? A Mathematical Proof

    Operations on infinite decimal representations need to be considered more carefully.
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    Undergrad What Does a Convolution of a Convolution Look Like?

    I should think something along these lines: (f*g)(t) \stackrel{\mathrm{def}}{=} \displaystyle\int_{-\infty}^\infty f(x)g(t - x) dx (h*(f*g))(t) = \displaystyle\int_{-\infty}^\infty h(y)(f*g)(t - y) dy = \displaystyle\int_{-\infty}^\infty h(y) \left( \displaystyle\int_{-\infty}^\infty...
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    What's on Your Fall 2010 Science Schedule?

    Object Oriented Programming Database Systems Networking Software Engineering Artificial Intelligence Geometric Transformations Topology I am very nervous about it, but I always overload myself and tend to turn out okay.
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    Graduate Simple Proof of Riemann's Hypothesis

    Doesn't the series definition only correspond to the Riemann Zeta function for Re(s) > 1?
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    Derivative Question- Chain Rule

    Are you trying to differentiate h(x) = sin [(x2 + 1)2] ? I'm currently having a hard time following your procedure (with the switching around of the h's and f's and u's and g's).
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    Good linear algebra book recommendation

    One of my professors recommended "The Linear Algebra a Beginning Graduate Student Ought to Know" by Jonathan Golan. I am currently working through it right now, and I am enjoying it thoroughly, as it is a little more involved than the textbook I had for my undergraduate linear algebra course...
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    Undergrad What is the difference between symmetric and antisymmetric relations?

    Yes, it is easy to draw a graph that represents a relation. Unfortunately, I can't find a link to any good examples at the moment. It's not too difficult, just pick up a piece of paper and try this. Let's say you have a set S = {a, b, c} and a relation R = {(a,b), (a,c)} on S. First, you want...
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    Undergrad What is the difference between symmetric and antisymmetric relations?

    Your language is kind of confusing to me with that "never" and those "nots". (I have dyslexia.) Basically, if you have a symmetric relation, then if you see (x,y) in your relation, you will also see a (y,x). Note that x and y might not be distinct. So if you have (x,x), it counts because you...
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    Undergrad What is the difference between symmetric and antisymmetric relations?

    http://en.wikipedia.org/wiki/Antisymmetric_relation From what I can tell, if you have a relation R on a set, then it is anti-symmetric if the following holds: If x,y are in the set and both (x,y) and (y,x) are elements of R, then x = y, or \mathrm{If} \ (x,y) \in R \ \mathrm{and} \ (y,x) \in...
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    Graduate Steps for Solving the Time Independent Schrodinger Equation for a Free Particle

    An equation of the form y(x) = c_1 e^{i\sqrt{k}x} + c_2 e^{-i\sqrt{k}x} would also solve the ODE, but that technique made use of the definitions \cos x = \frac{e^{ix} + e^{-ix}}{2} \sin x = \frac{e^{ix} - e^{-ix}}{2i} to get rid of the imaginary units.
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    Graduate Steps for Solving the Time Independent Schrodinger Equation for a Free Particle

    Take this with a grain of salt, as I am doing it completely from memory. If you have y'' = -ky, then y = erx is a solution since y'' = r2erx, and substituting this into the original ODE you have r2erx = -kerx ==> r2 = -k ==> r = +/- sqrt(-k) then r = +/- i sqrt(k) therefore let y_1 =...
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    Undergrad Differnece between the Kernel and the Nullspace?

    My professors have always used only the term Kernel, in both linear algebra and abstract algebra. Of course when referring to the vector space R^n and matrices, I can see how the term Null Space would go well with Vector Space, Column Space, etc.
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    High School Question about cadinality of sets

    Every element of a set is unique, therefore {1,2,2,3,3,1,1,1} is the same as {1,2,3}.