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Homework Help: A simple trig. problem.

  1. Nov 22, 2005 #1
    Q. Solve: secx=-5.2
    x is greater than or equal to zero and less than or equal to 2π

    I got 1.76 and 4.52, but answer key only has 1.76.

    Am I not right?
     
  2. jcsd
  3. Nov 22, 2005 #2
    I find the same answers as you do when I do a quick check using my TI-89. Hmmm :confused:
     
  4. Nov 23, 2005 #3

    VietDao29

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    Yup, that looks good to me. :smile: Your answer is correct!
     
  5. Nov 23, 2005 #4
    Thank you!
     
  6. Nov 23, 2005 #5

    Ouabache

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    Once you had the first solution 1.76, how did you find the 2nd one?
     
  7. Nov 24, 2005 #6

    VietDao29

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    Since you have cos(-x) = cos(x), and [itex]\cos x = \cos (x + 2k \pi) \ \ , k \in \mathbb{Z}[/itex]
    So the second one is just:
    [tex]- 1.76 + 2 \pi = 4.52[/tex]
     
  8. Nov 24, 2005 #7

    Ouabache

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    Thanks for answering, but I was asking dragon513.
    dragon513, what was your approach for finding the 2nd angle?
     
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