Recent content by GuiltySparks

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    Static magnet attached to a fridge

    Hi all, I had a thought earlier about magnetic forces. If there's a magnet attached (at rest) to my fridge, then there is a magnetic force on the magnet towards the fridge and vice-versa. This force stops the magnet from falling because of the frictional force between the magnet and the...
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    Convolution of a Gaussian with itself from the definition

    Homework Statement Find the convolution of g(x) = e^{-πx^{2}} with itself from -∞ to ∞ using the definition of convolution, not the Fourier Transform. The Attempt at a Solution See my attachment. My professor said that you have to use integration by parts, but I keep getting stuck...
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    Linear Algebra - dimension of orthogonal complement

    I've attached a copy of the problem and my attempt at a solution. This seems like a relatively straightforward question to me, but my answer seems to be the exact opposite of what the answer key says. I reach the conclusion that the answer is C, but the answer is apparently D. I'm...
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    RLC inverse Laplace transform question

    To clarify, both DC sources in the circuit are step inputs? If so, you need to represent them as a heaviside function in the s-domain (or u_0(t)), like I did in the previous derivation. Though, I do have the sneaking suspicion that you are incorporating these into the circuit to account for the...
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    Inverse Laplacetransform, can't find fitting formula

    Yes, we can use the definition of sinh and cosh. Hyperbolic sine: (e^2x - 1)/(2e^x) Hyperbolic cosine: (e^2x + 1)/(2e^x) 3(e^-t)[(e^2rad3(t) + 1)/(2e^rad3(t))] + (4/rad3)(e^-t)[(e^2rad3(t) - 1)/(2e^rad3(t))] =3(e^2rad3(t) + 1)/(2e^(rad3(t)+1)) + (4/rad3)(e^2rad3(t) - 1)/(2e^(rad3(t)+1))...
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    Where Can I Find Free Materials to Learn Calculus & Differential Equations?

    Paul's Calculus Notes is a great resource. Use it myself.
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    Critical points of a trig function

    Remember your unit circle. Taking the inverse cosine of (1/pi) points to one of two possible triangles that lie on this circle. From the argument, we know that the x-component of this circle will be 1; the hypotenuse will be pi. Remember that the hypotenuse will always be positive but the x- or...
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    Inverse Laplacetransform, can't find fitting formula

    Let's complete the square of the polynomial equation to get it into a form that we can use. s^2 + 2s -2 = (s+1)^2 -3 Now, we have 3s/[(s+1)^2 -3] + 7/[(s+1)^2 -3] = 3(s+1)/[(s+1)^2 -3] + 4/[(s+1)^2 -3] invLaplace => 3(e^-t)hcos(rad3*t) + (4/rad3)(e^-t)hsin(rad3*t)
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    RLC inverse Laplace transform question

    Doing it was actually pretty informative for me, also. I realized that if you take your source to be Vin/s, then that assumes the voltage on the circuit is always Vin for all time t. You would then need to account for initial conditions when doing the Laplace Transform; incorporating a heaviside...
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    RLC inverse Laplace transform question

    I worked out the solution and attached it. Notice that I assume at time t = 0 a DC step function is applied. You will have to minimize the amplitude of the trigonometric function. To do this, compute the partial derivatives of the amplitude A with respect to L, R, and C and set them equal to...
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    RLC inverse Laplace transform question

    First of all, let's use some of our intuition regarding circuits - intuition that every electrical engineer should have, that is - and predict the activity of this circuit. Notice that the input voltage is Vi/s; this corresponds to a DC signal of magnitude Vi that is applied to the circuit for...
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