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Homework Help: Drawing a right triangle to simply the given expressions

  1. Feb 18, 2012 #1
    1. The problem statement, all variables and given/known data

    Cos(Tan^-1(x))

    2. Relevant equations



    3. The attempt at a solution
    Dont know how drawing a right triangle would do anything, dont know what to plug in.
     
  2. jcsd
  3. Feb 18, 2012 #2

    Dick

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    Homework Helper

    Draw a triangle with an angle whose tangent is x. Any one. For example, opposite side equals x and adjacent side equals 1. Then find the hypotenuse using the pythagorean theorem.
     
  4. Feb 18, 2012 #3
    Have another question for a whole new problem...did not want to start a new thread because i felt some people would think i would be spamming.



    1. The problem statement, all variables and given/known data
    Sin(sec^-1(sqrt(x^2+16)/4))

    2. Relevant equations



    3. The attempt at a solution
    I did the math and ended up getting x^2-1 as the opposite, but the answers on the back of the book say other wise.
     
  5. Feb 18, 2012 #4
    Bump!
     
  6. Feb 19, 2012 #5

    HallsofIvy

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    This was answered in the "Precalculus homework" section.
     
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