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Math Help - Determining Exact Values

  1. #1
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    Determining Exact Values

    Hello. Would like some help please.

    Okay, so:

    tan(7Pi/4)
    = -tan(Pi/4)
    = -1


    I understand how it's -tan, and how it equals -1, but how/why did the brackets change from (7Pi/4) to (Pi/4)??? :/
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  2. #2
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    Re: Determining Exact Values

    Quote Originally Posted by ShootMePlease View Post
    Hello. Would like some help please.

    Okay, so:

    tan(7Pi/4)
    = -tan(Pi/4)
    = -1


    I understand how it's -tan, and how it equals -1, but how/why did the brackets change from (7Pi/4) to (Pi/4)??? :/
    Because \displaystyle \begin{align*} \frac{7\pi}{4} = 2\pi - \frac{\pi}{4} \end{align*}, which is in the fourth quadrant.

    So it's basically asking you to evaluate \displaystyle \begin{align*} \tan{\frac{\pi}{4}} \end{align*}, but to then take into account the fact that the tangent function is negative in the fourth quadrant.
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  3. #3
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    Re: Determining Exact Values

    Thank you! That makes much more sense now.
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