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burhan101

  • 2 years ago

Help me find the derivative of this function

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  1. burhan101
    • 2 years ago
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    \[\huge A(t)= 20\sin^2(\frac{ t }{ 1000\pi })\]

  2. bahrom7893
    • 2 years ago
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    Use power + chain rules

  3. bahrom7893
    • 2 years ago
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    This is a very straightforward question.

  4. burhan101
    • 2 years ago
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    |dw:1371609626141:dw|

  5. burhan101
    • 2 years ago
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    like that?

  6. bahrom7893
    • 2 years ago
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    you forgot the final chain rule

  7. primeralph
    • 2 years ago
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    |dw:1371609898205:dw|

  8. burhan101
    • 2 years ago
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    @bahrom7893 what do you mean?

  9. bahrom7893
    • 2 years ago
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    |dw:1371610057029:dw|

  10. primeralph
    • 2 years ago
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    |dw:1371610058623:dw|

  11. burhan101
    • 2 years ago
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    @bahrom7893 wait i dont get it tho, why the extra fraction :S

  12. bahrom7893
    • 2 years ago
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    derivative of |dw:1371610223598:dw|

  13. bahrom7893
    • 2 years ago
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    |dw:1371610328327:dw|

  14. burhan101
    • 2 years ago
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    |dw:1371610801029:dw| @bahrom7893

  15. bahrom7893
    • 2 years ago
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    Noooo

  16. Abhishek619
    • 2 years ago
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    |dw:1371610749100:dw|

  17. bahrom7893
    • 2 years ago
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    Guys stop confusing him. Burhan, your first answer was right. You just forgot to add in that fraction.

  18. burhan101
    • 2 years ago
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    How do i simplify further ?

  19. bahrom7893
    • 2 years ago
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    just use algebra, cancel out some fractions.

  20. burhan101
    • 2 years ago
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    howww im really confused !!

  21. burhan101
    • 2 years ago
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    The answer key says it should be \[\huge A'(t) = \frac{ 1 }{ 50\pi }\sin (\frac{ t }{ 50\pi })\]

  22. burhan101
    • 2 years ago
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    @bahrom7893

  23. bahrom7893
    • 2 years ago
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    2Sin(x)Cos(x) = ? (double angle formula)

  24. burhan101
    • 2 years ago
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    if i just simplify that fraction to 'x' then =20((2sinx)(cosx)(x)) =20(xsinx)

  25. primeralph
    • 2 years ago
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    .just use what I gave if you're still confused....

  26. bahrom7893
    • 2 years ago
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    |dw:1371612098284:dw|

  27. bahrom7893
    • 2 years ago
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    so according to our calculations, the answer should be: |dw:1371612290008:dw| which seemed right. the book might have a typo

  28. primeralph
    • 2 years ago
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    ........which is what I said 40 minutes ago........ |dw:1371612421231:dw|

  29. bahrom7893
    • 2 years ago
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    lol

  30. burhan101
    • 2 years ago
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    thanks both !@bahrom7893 @primeralph

  31. primeralph
    • 2 years ago
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    You're very welcome.

  32. bahrom7893
    • 2 years ago
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    np my friend :)

  33. burhan101
    • 2 years ago
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    b) What is the first value of t greater than 0 for which the derivative is equal to 0?

  34. burhan101
    • 2 years ago
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    @primeralph

  35. bahrom7893
    • 2 years ago
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    set the derivative equal to 0, then check the signs nearby

  36. burhan101
    • 2 years ago
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    @primeralph what does that mean ^ ?

  37. primeralph
    • 2 years ago
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    for it to equal zero, you have to shift t by the period pi

  38. primeralph
    • 2 years ago
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    |dw:1371615489438:dw|

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