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Thread: Half Angle Fromula

  1. #1
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    Exclamation Half Angle Fromula

    If t = tan1/2ě

    Then show that:

    sině = 2t/1+t^2

    I have deduced that:

    sin2A=2tanA/1+tan^2A

    But am unsure how to get from the second formula to the first.
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  2. #2
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    Re: Half Angle Fromula

    Hey KiaraG16.

    Hint - Let A = 1/2.
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  3. #3
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    Re: Half Angle Fromula

    Oh I see, so because A could equal any angle it could also equal 1/2*Theta which is why the second equation remains the same as the first?
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  4. #4
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    Re: Half Angle Fromula

    That's basically the idea.
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