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Homework Help: Differentiating trig

  1. Jan 12, 2010 #1
    1. The problem statement, all variables and given/known data

    we have been doing some error analysis in school, but they were very straight forward for example. Centripetal Acceleration : Fc = 4pi^2 m R / T^2


    however, for my project i must find the uncertainty in the angle that i measured.
    the angle is formed by a cardboard sitting on pile of books creating a triangle.
    Hypothenus = 33cm
    Height = Variable ( Changes according to the stack of the book)

    please help !! differentiate theta = inverseSin(Opposite/Hypothenus)




    2. Relevant equations

    theta = inverseSin(Opposite/Hypothenus)

    3. The attempt at a solution

    well since i measurd these distances with a ruler

    the uncertainty for hypothenus would be +- 0.005m (last half digit of a number)
    and the uncertainty for heght is the same + - 0.005m (last half dight of a number)

    how do i use these to differentiate for one another?
    which formurla woudl i use pleaes help !!
     
  2. jcsd
  3. Jan 12, 2010 #2

    rl.bhat

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    Homework Helper

    If x = a/b, then the maximum error in measurement is
    Δx/x = Δa/a + Δb/b
     
  4. Jan 12, 2010 #3
    d(theta)=1/sqrt(1-(o/h)^2)

    now how should i ???

    HELP plz just differentiate for opposite and hypothenus for me please...
     
  5. Jan 13, 2010 #4

    rl.bhat

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    Homework Helper

    d(theta)=1/sqrt(1-(o/h)^2)
    From where did you get this expression?
    What it represents?
     
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