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Math Help - Law of cosines...please help...urgent

  1. #1
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    Law of cosines...please help...urgent

    could someone please assist me with this problem (number 16) ...when I put sin^-1 (1.504) i get an error on my calculator...I don't know what I am doing wrong...
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  2. #2
    MHF Contributor kalagota's Avatar
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    Quote Originally Posted by aikenfan View Post
    could someone please assist me with this problem (number 16) ...when I put sin^-1 (1.504) i get an error on my calculator...I don't know what I am doing wrong...
    there is really wrong with it.. take note that -1 \leq sin \theta \leq 1, and you got sin B = 1.504 which is out of range..

    now, i noticed that angle A = 110^o > 90^o, which means that the side opposite A must be longer that any other sides.. maybe, there is something wrong with the given.., or else, no triangle is formed..
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  3. #3
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    Hello, aikenfan!

    You're doing nothing wrong.
    The problem is a trick question . . .


    A = 110^o,\;a = 125,\;b = 200

    Try to sketch the triangle . . .
    Code:
        B *
           *
            *
             *            *
              *               *   a = 125
               *                  *
                *                     *
                 * 110                   *
                  *   *   *   *   *   *   *   *
                 A           b = 200              C

    We can see that side a is too short.
    . . There is no triangle.

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  4. #4
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    Wow! Thank you very much...no wonder I have been having so much trouble (and got an error message)!
    Thanks!
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