Recent content by apw235

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    Solving Dirac Delta Cosx: Find Range of n and a_n, x_n

    Homework Statement The function \delta(cosx) can be written as a sum of Dirac delta functions: \delta(cosx)=\sum_{n} a_{n}\delta(x-x_{n}) Find the range for n and the values for a_{n} and x_{n} The Attempt at a Solution Well, taking the integral of \delta(cosx), we only get spikes when...
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    Purcell's Electricity and Magnetism - question

    anybody?
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    Purcell's Electricity and Magnetism - question

    Homework Statement Purcell 3.3: In the field of a point charge over a plane, if you follow a field line that starts at the point charge in a horizontal direction, that is, parallel to the plane, where does it meet the surface of the conductor? Homework Equations The problem 'hint' is...
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    Simple Partial Derivatives Question

    i know the chain rule but do i use .15 as dT/dt and .1 as dR/dt? then it becomes extremely trivial, i thought it would be more involved...oh well
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    Simple Partial Derivatives Question

    Homework Statement Wheat production in a given year, W, depends on the average temperature T and the annual rainfall R. Scientists estimate that the average temperature is rising at a rate of 0.15 degrees celsius per year and rainfall is decreasing at a rate of 0.1 cm per year. The also...