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  1. #1
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    HELP differentation

    v=340*e^-2t sin wt where f=4Hz so w= 8pi

    1) find the rate of change of v with respect to t at t=15ms

    2) sketch the waveform of v for t=0 to 1s
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  2. #2
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    Quote Originally Posted by bobbym View Post
    v=340*e^-2t sin wt where f=4Hz so w= 8pi

    1) find the rate of change of v with respect to t at t=15ms

    2) sketch the waveform of v for t=0 to 1s
    v=340e^{-2t}\sin(\omega t)

    \frac{dv}{dt}=340[-2e^{-2t}\sin(\omega t)+e^{e^{-2t}}\omega\cos(\omega t)]=340e^{-2t}[\omega \cos(\omega t)-2\sin(t)]

    Just evalute from here Remember that 15ms =0.015s

    Here is a graph

    HELP differentation-wave.jpeg
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  3. #3
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    did u use the chain rule to do the 1st part if so what are the steps for it please
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  4. #4
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    help do i use the chain rule

    when i differentiate v=340*e^-2t sin wt where f=4Hz so w= 8pi with repect to t do i used the chain rule if so what are the steps to differentiating it
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  5. #5
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    Quote Originally Posted by bobbym View Post
    did u use the chain rule to do the 1st part if so what are the steps for it please
    v=340e^{-2t}\sin(\omega t) is a product so the product rule was used.
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  6. #6
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    what are the steps to doing the product rule on this equation please
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  7. #7
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    Quote Originally Posted by bobbym View Post
    what are the steps to doing the product rule on this equation please
    Are you familiar with the product rule? Have you used it before?
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  8. #8
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    i have used it a few times and get the basics of it but have not done 1 this complicated
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  9. #9
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    Quote Originally Posted by bobbym View Post
    i have used it a few times and get the basics of it but have not done 1 this complicated
    h(t) = f(t) g(t) => h'(t) = f(t) g'(t) + f'(t) h(t).

    In your case f(t) = 340 e^{-2t} and h(t) = sin (wt).

    Get f'(t) and g'(t). Substitute f(t), f'(t), g(t) and g'(t) into the rule.
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  10. #10
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    what wud that look like with my figures in plz
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  11. #11
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    Quote Originally Posted by bobbym View Post
    what wud that look like with my figures in plz
    Go back and read post #2.
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