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    Derivative Question

    Oh, I see it now. Thanks.
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    Derivative Question

    Also, where would apply the chain rule here? I don't see it.
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    Derivative Question

    ok, could you elaborate on that a little. I know what the chain rule is but I don't see it's application here. The result ought to be the same regardless of when I plug in the value of the radius (in this case c/2pi). I don't see why the value of the radius would ever change. That seems like it...
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    Derivative Question

    Homework Statement Find the derivative of volume of a sphere. Homework Equations Volume=4/3 * pi * r^3 OR Volume = 4/3 * pi * (c/2pi)^3 where c=circumference The Attempt at a Solution This is where I have had some serious trouble. Allow me to explain. Obviously the...
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    Very strange question for derivative

    Wow, good catch. I didn't realize the contradiction. The way I stated the problem is all the info given to me by the question. The problem asks to find the slope of the tangent at the point where x=a. A is an x value, not a point. The problem does not tell me what a is. I will edit the...
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    Very strange question for derivative

    Homework Statement The question in it's complete wording: Consider the following curve. y = 8 + 5x2 - 2x3. Find the slope of the tangent to the curve at the point where x = a. Homework Equations (y2-y1)/(x2-x1) where x2=x1+dx and the limit of dx is approaching zero and y2=f(x+dx). The...
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    Question about two charges on a line.

    thanks for your help. i asked my teacher to work it with me today and he clarified.
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    Question about two charges on a line.

    ehild, I am sorry to be so stubborn, but I still don't see how to come any closer to the answer. Let's say I put a test charge of 1.00 Coulomb at the position (3.00m, 0.00m). Now the equation I will use will be: E = KQ1/r2 + KQ2/r2 Going by this and using the numbers I have chosen for my...
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    Question about two charges on a line.

    how would i set that equal to zero?
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    Question about two charges on a line.

    i think you are talking about E=kQ/r^2
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    Question about two charges on a line.

    That makes sense to me but I am not sure where to go from there. Can you suggest a formula to do that? I am still not sure what to do with the problem.
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    Question about two charges on a line.

    Homework Statement A charge of 5.00mC is at the point (1.00m, 0.00m) and a charge of -4.00 is at the point (-1.00m, 0.00m). At what point, or points, on the x-axis is E=0? Homework Equations I decided to use the equation for voltage and set it up like this: E = 0 = (k)(Q1) / x +...
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    Speaker hanging from the ceiling

    please help. i have a test in a few hours.
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    Speaker hanging from the ceiling

    Homework Statement A 19.0 kg speaker is suspended 1.6m from the ceiling by two cables each 2.5m in length. the cables come to the top of the speaker and each cable forms and equal angle with the ceiling. Homework Equations i have no idea. i am completely lost. The Attempt at a...
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