Recent content by cristina89

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    Graduate What is a Collineation and How Does it Differ from an Affine Transformation?

    Hello people! I'm studying about collineation. It seems to be simple, but I can't understand so much and I can't find so many things about this subject... Can someone explain to me what exactly is a Collineation? Is this the same thing as Affine Transformation? Is there examples that...
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    Find Minimal Polynomial for Matrix: Solution Help

    Homework Statement Given the matrix 2 0 0 0 0 0 0 1 2 0 0 0 0 0 0 1 2 0 0 0 0 0 0 1 2 0 0 0 0 0 0 0 2 0 0 0 0 0 0 1 2 0 0 0 0 0 0 0 2 What is the minimal polynomial? Homework Equations - The Attempt at a Solution This is the Jordan form, so I guess the solution is just...
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    Limit Comparison Theorem: Proving the Relationship Between Two Functions

    Homework Statement Prove that if f(x)<=g(x) then lim f(x) <= lim g(x).Homework Equations -The Attempt at a Solution I've tried by definition of limit, but I didn't get anywhere with this... Can anyone help me??
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    Is T^n Linear When T is Linear?

    I'm trying to solve it by induction. For n = 1 ok. Assuming that's ok for n = k. For n = k+1 I don't know if I'm doing it right in this part: Tk+1 = Tk.T(u+v) = Tk.(T(u+v)) = Tk(T(u)) + Tk(T(v)). Can I just afirm that's ok since T(u+v) is an application and Tk is an application too?
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    Is T^n Linear When T is Linear?

    Homework Statement If T is a linear transformation, proof that Tn is a linear transformation (with nEN). Homework Equations I know that T is a linear application if: T(u+v) = T(u) + T(v) T(au) = aT(u) The Attempt at a Solution Actually I don't know how to start using these two...
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    Undergrad Green's, Stokes and Divergence Theorem

    When the exercise tells me to calculate the flux, how do I know when I need to use each of these theorems (Green's, Stokes or Divergence)? Can anyone tell me the difference between them? I'm a LOT confused about this. If anyone knows any good material about this on internet, it'll help me a...
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    Christoffel Symbol / Covariant derivative

    Homework Statement My teacher solved this in class but I'm not understanding some parts of tis solution. Show that \nabla_i V^i is scalar. Homework Equations \nabla_i V^i = \frac{\partial V^{i}}{\partial q^{i}} + \Gamma^{i}_{ik} V^{k} The Attempt at a Solution To start this...
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    Is B^{ij}_i a Contravariant Vector?

    Homework Statement B is a third order tensor. Show that B^{ij}_{i} is a contravariant vector. The Attempt at a Solution Well... I just thought about a simple solution but I don't think I'm right. But anyways. Considering B^{ij}_{i}. If I raise the index i: g^{ij}B^{ij}_{i} = B^{ijj} And...
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    Flux of a Vector Through a Surface: x²+y²=8, z-x²-y²=0

    Thank you! Is it right to bound the integrals like this \int^{2∏}_{0}\int^{8}_{0}?
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    Flux of a Vector Through a Surface: x²+y²=8, z-x²-y²=0

    Can't I think that \hat{n} = \frac{v}{|v|} = \frac{v_{0}x\hat{z}}{\sqrt{v_{0}^{2}x^{2}}} = \hat{z}? And then \int\int{v_{0}x\hat{z}\hat{z}dS}? Can you explain to me this "\hat{z}\cdot\hat{n} is cos of the slope of the normal (= sin of the slope of the surface)"? :S I can't understand that...
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    Flux of a Vector Through a Surface: x²+y²=8, z-x²-y²=0

    ahh ok. so \int\int{v_{0}x}(\hat{z}\cdot\hat{n})dS = \int\int v_{0}x(\hat{z})\frac{v_{0}x\hat{z}}{\sqrt{v_{0}^{2}x^{2}}} right? What should I do after that? I'm now confused if there is this normal vector in this integral. Is this correct?
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    Flux of a Vector Through a Surface: x²+y²=8, z-x²-y²=0

    Homework Statement The velocity of a fluid is given, in cartesian coordinates (x, y, z), by \vec{v} = v_{0}x\hat{z} being a constant with velocity dimensions. a) Calculate the flux of this vector through the closed surface composed by z-x²-y²=0 and by the plan z=8 limited by the circle with...
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    Undergrad Good book about Vector Calculus?

    Thank you so much! I'll try to find this book tomorrow. I just need to have an idea of how, given a transformation, I find a new basis, a normalized basis, the displacement, gradient, the volume in the new basis... This kind of thing. If anyone else knows any other book, please tell me, it...
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    Undergrad Good book about Vector Calculus?

    I'm studying Vector Calculus right now, and I'll have a test about Coordinate Transformation soon. But the book my teacher recommended (Mathematical Methods for Physicists - Arfken) is way too hard to understand this subject. Does anyone know any good material about this that I can find on...