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Math Help - trig

  1. #1
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    trig

    sec^2x * tanx = 2tanx
    in [0, 360) interval
    find degree of x

    Do I subtract 2tanx then use tan^2+1 = sec?
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  2. #2
    Senior Member vincisonfire's Avatar
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    \frac{sin(x)}{cos^3(x)}= 2\frac{sin(x)}{cos(x)}
    \frac{1}{2} = cos^2(x)
     \pm \sqrt{\frac{1}{2}} = cos(x)
    Can you find the answer now?
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  3. #3
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    Yes, thanks.. but i did it like this and it worked....
    sec^2x * tanx = 2tanx
    and i divided tanx from the both sides and got..
    tan^2x+1=2 then..
    tan^2x=1and finally..
    tanx=+/-1

    That way can work too right?
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  4. #4
    Senior Member vincisonfire's Avatar
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    Of course it is even better. I have a tendency to complicate things.
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  5. #5
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    Hhaha okay.. thank you so much for your help, it actually helped me to get to that step haha.
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