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Homework Help: Solving a Trig Inverse.

  1. Nov 29, 2008 #1
    1. The problem statement, all variables and given/known data
    Solve arctan 3x + arctan 2x= pie/4?

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Nov 29, 2008 #2
    there is a trig identiy that helps.

    arctan[x]+arctan[y] = arctan[(x+y)/(1-xy)]

    then it is just the angle that has a tan of pi/4 (i am assuming radians), so 1

    then solving 5x/(1-6x^2)=1 we get x= 1/6 and x=-1
    reject the -1 as the domain of arctan does not include it if is re-inserted into the fuction.
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