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Homework Help: How to deal with INVERSE TANGENT?

  1. Oct 22, 2013 #1
    1. The problem statement, all variables and given/known data

    Find X. Given the following Equation

    2.094 radians =tan^-1(2*x*(1.11)/1-(1.11)^2)

    2. Relevant equations

    3. The attempt at a solution

    How do you get rid of inverse tangent?

    Here's what i got

    tan(2.094((180/pi))*(1-(1.11)^2) / 2*1.11 = X
    Last edited: Oct 22, 2013
  2. jcsd
  3. Oct 22, 2013 #2


    Staff: Mentor

    This -- (2*x*(1.11)/1-(1.11)^2) -- is missing some parentheses.

    Is it supposed to be this?
    $$ \frac{2x \cdot 1.11}{(1 - 1.11)^2}$$

    Take the tangent of both sides.
  4. Oct 22, 2013 #3
    No, the 1.11 in the denominator is squared instead of (1-1.11)^2

    So the denom is


    Sorry my mistake
  5. Oct 22, 2013 #4
    You are doing the right thing, taking the tangent of both sides. However you do not want to use the ##180/\pi## which converts radians to degrees. (Also, if you really wish to convert back to degrees, you have to convert everything, not just one factor. )

    Usually if there is an x involved we assume we are in radians, which are really arclength, and so compatible with lengths on the x-axis.

    Go ahead and compute it out.
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