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Math Help - trig equation involving tan

  1. #1
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    trig equation involving tan

    Hello, I am looking at this trig equation: tan^2(3x) = 1 (for values of x greater than or equal to zero and less than or equal to 2pi)
    I can understand how to solve it almost right to the end.
    I can get to the point where I have tan3x=1 and tan3x = -1. I then get +- 45 degrees. I know I need to divide that by 3, so I end up with 15 degrees.
    I know the final answer is:
    +-pi/12 + pi/3(k)
    But I dont understand this answer.
    The problem I am having is plotting those points on a tan graph.
    Could someone please tell me the exact values that the answer above represents and where they sit on the tan graph.
    Then I can visualize it and understand better.

    Thanks kindly for any help.
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  2. #2
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    Re: trig equation involving tan

    15 degree is the same as pi/12, then you are just adding the period of the function for repeated solutions.
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  3. #3
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    Re: trig equation involving tan

    thanks. I am still trying to understand how the correlates with the answer "+-pi/12 + pi/3(k)"
    I see the pi/12 = 15 degree, but then what about the last part "+pi/3(k). Isnt that adding 60 degrees to each unit of 15 degree ? Should'nt it be + 180 degrees (pi) ?

    Thanks for clarification.
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  4. #4
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    Re: trig equation involving tan

    \tan x has a period of \pi

    \tan nx has a period of \frac{\pi}{n}
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  5. #5
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    Re: trig equation involving tan

    Moved thread to Trig.
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