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Homework Help: Solving Angles

  1. May 26, 2008 #1
    1. The problem statement, all variables and given/known data

    find the values of a to 1 decimal place for the interval 0 <= a <= 360 for which

    5sin (a+30) = 3


    3. The attempt at a solution
    I know this is really easy but i've forgotten the method :(


    somthing like

    (a + 30) = arcsin(3/5)
    a + 30 = 36.869...

    but im not sure where to go from there.

    Thanks
     
    Last edited: May 26, 2008
  2. jcsd
  3. May 26, 2008 #2

    HallsofIvy

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    How about subtracting 30 from both sides?
     
  4. May 26, 2008 #3

    HallsofIvy

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    What do you get if you subtract 30 from both sides?
     
  5. May 26, 2008 #4
    a = 6.8....
    so

    a = 6.8, 180 - 6.869..,
    a = 6.8 and 173.1...
    is that my final answer?
     
  6. May 26, 2008 #5

    Redbelly98

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    Looks good, how about checking those numbers back in the original equation? Then you can be sure.

    I.e., does 5sin(6.869+30) equal 3? And similarly for 173.131
     
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