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Math Help - trig

  1. #1
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    trig

    determine arcsin(sin(x)) for Pi/2 < x <3Pi/2
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  2. #2
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  3. #3
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    Quote Originally Posted by dwsmith View Post
    I dont really understand whats going on in that thread =\
    How would i calculate it in an exam? like with no calculator or stuff...
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  4. #4
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    Lets start by saying y=arcsin(sinx) then.

    Now if we take the sin of both sides, we have siny=sinx

    What values of x and y in the interval will satisfy this equation?
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  5. #5
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    Quote Originally Posted by dwsmith View Post
    Lets start by saying y=arcsin(sinx) then.

    Now if we take the sin of both sides, we have siny=sinx

    What values of x and y in the interval will satisfy this equation?
    all values?....
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  6. #6
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    So if x=-pi and y=2, siny=sinx?

    When x=y they will be equal. What angle does that occur at?
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  7. #7
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    Quote Originally Posted by dwsmith View Post
    So if x=-pi and y=2, siny=sinx?

    When x=y they will be equal. What angle does that occur at?
    dw... your rhetorical questions fail at life.
    i worked it out myself
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  8. #8
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    Would you have learned anything if my first post just said 5pi/4 + (2pi)k or -3pi/4 + (2pi)k.
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  9. #9
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    Quote Originally Posted by dwsmith View Post
    Would you have learned anything if my first post just said 5pi/4 + (2pi)k or -3pi/4 + (2pi)k.
    no cause thats not the answer.....
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  10. #10
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    Here is the proof pg 3.

    x=arcsin(sinx)

    I said say y=arcsin(sinx) and then ended with when y=x.

    http://www.math.tamu.edu/~austin/section4_6.pdf
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  11. #11
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    Quote Originally Posted by dwsmith View Post
    Here is the proof pg 3.

    x=arcsin(sinx)

    I said say y=arcsin(sinx) and then ended with when y=x.

    http://www.math.tamu.edu/~austin/section4_6.pdf
    sorry can you stop failing? the answer is Pi -x..... i wanted someone to explain it...
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  12. #12
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    You should work on your trig. Do you even know what the difference between it equaling x or pi - x?

    It has to do with what side of the y axis you are on.
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  13. #13
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    Quote Originally Posted by dwsmith View Post
    Would you have learned anything if my first post just said 5pi/4 + (2pi)k or -3pi/4 + (2pi)k.
    dwsmith, I think you've got something wrong here. I think you are attempting to solve sin x = cos y.
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  14. #14
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    Quote Originally Posted by dwsmith View Post
    You should work on your trig. Do you even know what the difference between it equaling x or pi - x?

    It has to do with what side of the y axis you are on.
    i think you have to work on explaining things and actually getting the solution the person wants instead of waffling
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