Recent content by icurays1

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    Quick & easy transistor question

    Glad I could bring up an exciting topic! haha.. I have another real question: I have some power transistors now, which I have chosen somewhat arbitrarily based on their max power dissipation (I need ~ 1watt for total RF power, so I got a couple transistors in the 5-10W max range). How do I...
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    Quick & easy transistor question

    Awesome! Thanks. Is there a not quick & dirty answer? I suppose I should just give it a shot first and keep reading my book if I want a more in-depth answer.
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    Quick & easy transistor question

    Hello, Thanks ahead for fielding my amateurish question - I'm a math guy and circuits are new to me. I'm trying to design a quick & dirty (aka need-not-be-linear) RF amplifier circuit and was wondering the following stupid thing: A lot of the circuits I've found are configured for NPN - if...
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    Graduate Is the Laplacian of a Function Simply the Trace of its Hessian Matrix?

    okay, cool. thanks! would the trace of an arbitrary tensor be \sum_{i}{A_{ii...i}} i.e. summing over the elements of the tensor with identical indicies? For tensors rank>2 'diagonal' is sort of vague, or does 'diagonal' always mean 'elements with the same index'? I guess this doesn't have...
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    Graduate Is the Laplacian of a Function Simply the Trace of its Hessian Matrix?

    But then isn't the 'Hessian' a tensor with co/contravariant components? is the trace even defined for tensors like that? And how is a differential operator like \nabla^2 even defined in a nonlinear coordinate system? (Genuine questions, I'm just starting to learn tensors and differential...
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    Graduate Is the Laplacian of a Function Simply the Trace of its Hessian Matrix?

    Stupid thing I noticed today: \nabla^2 U=tr(H(U)) Or, in other words, the Laplacian of a function is just the trace of its Hessian matrix. Whoop-de-frickin do, right? Is this useful knowledge or should I forget it immediately? N!
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    Undergrad Logical sequence of math topics

    That is perfect! Its not the easiest chart to use, but it certainly has lots of useful links. Thanks! Now I can go find books that are only 1 step above where I'm at instead of 10.
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    Undergrad Logical sequence of math topics

    I just found this forum and it looks great! I'm an undergrad Physics/applied math at Western Washington University in Bellingham, WA. I'm wondering if anyone has ever seen a kind of family-tree-type-deal of math topics. I have this problem with trying to read wikipedia articles and...