Recent content by Chaoticoli

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    How are these two equations equal? trig identities possibly?

    Homework Statement Proof that (1/6)sin(3x)-(1/18)sin(9x) = (2/9)sin^3(3x) Homework Equations The Attempt at a Solution I am just curious exactly how the power on the sine function is cubic on one side. It obviously has to do with something that increases the power on the...
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    Absolute convergence proving that limit =1

    I understand now. Thanks :)
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    Absolute convergence proving that limit =1

    It must alternate between -1 and 1.
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    Absolute convergence proving that limit =1

    Homework Statement limit as k--> infinity ABS VALUE((cos(pi*k+pi))/(cos(k*pi))) Homework Equations The Attempt at a Solution Can someone prove to me why this limit is equal to 1? I have tried several other sources and I have not had any luck.
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    Disc Method Finding Volume Trig Function

    Actually, I just figured it out :). I got 27pi^2 after integrating from -pi/2 to 3pi/2 of (3sin(x)-3)^2 dx
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    Disc Method Finding Volume Trig Function

    Yes. I visualize it being rotated, forming discs about the line y=7. Is it the distance between y=3sin(x)+4 and y=7? (3sin(x) + 4) - 7 = 3sin(x) -3 = r(x) ??
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    Disc Method Finding Volume Trig Function

    Obviously, I just need to find out what r(x) is and figure out if I should integrate with respect to x or y.
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    Disc Method Finding Volume Trig Function

    Homework Statement Consider the region of the x-y plane between the line y=7, the curve y=3sin(x)+4 , and for -pi/2<x<3pi/2 Find the volume of the solid generated by revolving this region about the line y=7. I know that for this problem, I will be using the disk method (as the title...