Recent content by SP90

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    Clarifying Integral Limits in Equation 4.6: A Scientific Analysis

    http://arxiv.org/pdf/0807.1310v5.pdf Equation 4.6 strikes me as wrong. The integral is \int_{0}^{\infty} B \mathrm{d}B The limits of the integral seem to be values of z, but the integral seems to be wrt B. If the limits were values of B, the answer would be ∞. It's clearly not, but I don't...
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    Trigonometric Identity Proof: v cosδ = V(1-cosβ) + u cos(α-β)

    This is now solved. It can be solved by extending the left triangle to a right-angled triangle, with a base of V+k (hence where the single V comes from). Then \cos{\delta}=V+k k is given by x \cos{(\pi-(\theta + \beta))}=-x \cos({\theta + \beta}). Using the cosine sum rule I stated above...
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    Trigonometric Identity Proof: v cosδ = V(1-cosβ) + u cos(α-β)

    Homework Statement Given the following two triangles: Show that v \cos{\delta} = V(1-\cos{\beta})+u\cos(\alpha - \beta) The Attempt at a Solution Using the cosine law I've got: v^{2}=x^{2}+V^{2}-2xV\cos{(\theta + \beta)} and u^{2}=x^{2}+V^{2}-2xV\cos{(\theta)} I figured maybe using the...
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    Conditional Probability Distribution

    But because the joint PMF is a multiplication of the individual PMFs, the term becomes \lambda_{1}^{n_{1}}\lambda_{2}^{n_{2}}\lambda_{3}^{n_{3}}... which means the term \sum_{i=1}^k N_i = n doesn't appear in the joint PMF (although it would if the \lambda_{i} were equal), so I don't understand...
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    Conditional Probability Distribution

    I don't understand how the \sum_{i=1}^k N_i = n term constrains the joint distribution, given that each \lambda_{i} can be distinct. Also, to evaluate P(\sum_{i=1}^k N_i = n), wouldn't this be the joint distribution, evaluated at N_{1}=n-\sum_{i=2}^{k}N_{i} and then...
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    Conditional Probability Distribution

    Homework Statement The Attempt at a Solution I have that the joint probability mass function would be \Pi_{i=1}^{k} \frac{\lambda_{i}^{n_{i}}}{n_{i}!} e^{-\lambda_{i}} How would I go about applying the conditional to get the conditional distribution?
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    Where did I go wrong in calculating the traction fields?

    Homework Statement Question (specifically part b): Solution: The Attempt at a Solution My issue is that I don't agree with \Gamma^{0}_{3} and \Gamma^{1}_{3}, surely if they're given by [S][n] they should be given by \mp(0,0,\rho g x_{3}). The answers they have don't make sense, because...
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    Using the Divergence Theorem to Solve Vector Calculus Problems

    Isn't \nabla \cdot v \otimes n = (n_{1}(\frac{dv_{1}}{dx_{1}}+\frac{dv_{2}}{dx_{2}}+\frac{dv_{3}}{dx_{3}}), n_{2}(\frac{dv_{1}}{dx_{1}}+\frac{dv_{2}}{dx_{2}}+\frac{dv_{3}}{dx_{3}}), n_{3}(\frac{dv_{1}}{dx_{1}}+\frac{dv_{2}}{dx_{2}}+\frac{dv_{3}}{dx_{3}})) Which is n \cdot \nabla v? This would...
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    Using the Divergence Theorem to Solve Vector Calculus Problems

    Homework Statement Homework Equations So I have that v \otimes n = \left( \begin{array}{ccc} v_{1}n_{1} & v_{1}n_{2} & v_{1}n_{3} \\ v_{2}n_{1} & v_{2}n_{2} & v_{2}n_{3} \\ v_{3}n_{1} & v_{3}n_{2} & v_{3}n_{3} \end{array} \right) The Attempt at a Solution I've tried applying the...
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    Solving a linear equation with a cross product

    Homework Statement Suppose v is a vector satisfying: \alpha v + ( a \times v ) = b For \alpha a scalar and a, b fixed vectors. Use dot and cross product operations to solve the above for v. Homework Equations The unique solutions should be: v=\frac{\alpha^{2}b- \alpha (b \times a) + (b...
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    Projection and Reflection of Vector WRT plane

    Ah, I see. So instead I use \hat{n}=\frac{1}{\sqrt{6}}(1i-2j+1k) and that gives Pv=\frac{1}{6}(25i+10j-5k). And Tv=\frac{1}{6}(32i-4j+2k). Is that right now?
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    Projection and Reflection of Vector WRT plane

    Makes sense, thanks for the quick response. I get 10i-10k+5k which, when dotted with n obviously gives 0. Correcting the sign error for the second yields 17i-24j+12k. Thanks for your help
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    Projection and Reflection of Vector WRT plane

    Homework Statement Given a plane \Pi with normal n=i-2j+k and a vector v=3i+4j-2k calculate the projection of v onto \Pi and the reflection of v with respect to \Pi. The Attempt at a Solution I need to check that I'm doing this is right. I think I need v - (v \cdot n)n =...
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    Buckingham Pi - Understanding Trader Behavior in Stock Markets

    Homework Statement A simple dynamical model for the price P (in £) of shares in a single stock or commodity traded in a stock market describes the behaviour of all the traders in the market with the same simple rule. All traders buy or sell shares at each "tick" (or time step \Delta t. To...
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    Proving there are infinitely many primes

    Homework Statement Prove that their are infinitely many primes such that \left(\frac{14}{p}\right)=1 Homework Equations The bracketed symbol is the legendre symbol (i.e. there are infinitely many primes such that 14 is a square modulo p) The Attempt at a Solution Well by...
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