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Homework Help: Help with inverse trig functions

  1. Sep 5, 2012 #1
    Here is my problem:


    my awnser:

    cot= x/(1-x)^1/2

    The online program were suppose to use says im wrong but im not sure what I did wrong.
  2. jcsd
  3. Sep 5, 2012 #2


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    What's the question that you're trying to answer?

    The answer you give makes no sense whatsoever.
  4. Sep 5, 2012 #3


    Staff: Mentor

    Draw a right triangle, with θ being the acute angle in the triangle. Let θ = arcsin(x), and label the sides and hypotenuse according to this definition.

    The problem boils down to evaluating cot(θ).

    Your answer SHOULD NOT start with "cot =" since cot by itself is meaningless in this context. If you are doing your work on paper, your work should start with cot(arcsin(x)) = ... and end up with what you found, which is actually not too far off.
  5. Sep 6, 2012 #4


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    The simplest way to do this is to imagine a right triangle with one angle [itex]\theta[/itex], "opposite side" to [itex]\theta[/itex] of length x, and hypotenuse of length 1 so that [itex]sin(\theta)= x/1[/itex] and thus [itex]\arcsin(x)= \theta[/itex].

    Now, what is the length of the near side and what is [itex]tan(\theta)= tan(arcsin(x))[/itex]?

    You are missing a square in your answer.
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