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Homework Help: Problem in finding the General Solution of a Trigonometric Equation v3

  1. May 19, 2017 #1

    Wrichik Basu

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    1. The problem statement, all variables and given/known data:

    Find the general solution of the Trigonometric equation: $$3\sin ^2 {\theta} + 7\cos ^2 {\theta} =6$$

    Given andwer: ##n\pi \pm \frac {\pi}{6}##

    2. Relevant equations:

    These equations may help:

    20170519_023122.png

    3. The attempt at a solution:

    Please see the pic below:

    14951886349821598693691.jpg

    It seems correct from my side, but the answer is not matching.
     
  2. jcsd
  3. May 19, 2017 #2

    BvU

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    Is there really a difference :smile: ?
     
  4. May 19, 2017 #3

    Wrichik Basu

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    Couldn't understand.... could you explain a bit...
     
  5. May 19, 2017 #4

    BvU

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    Fill in n = 1, 2, 3 in both expressions (yours and the book one) :rolleyes:
     
  6. May 19, 2017 #5

    scottdave

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    There is a pi radian difference between -pi/6 and 5pi/6, same with pi/6 and -5pi/6. So you can just say it is +-pi/6 + n*pi, where n can be any integer. That covers all of your scenarios.
     
  7. May 19, 2017 #6

    BvU

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    Why don't you let Wrichik make that discovery himself ?
     
  8. May 19, 2017 #7

    Wrichik Basu

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    understood. Thank you.
     
  9. May 19, 2017 #8

    scottdave

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    Thanks. I guess I didn't see your response about plugging in 1,2,3, etc when I wrote my suggestion.
     
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