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Help with reversing a function

  1. Sep 21, 2008 #1
    I need to know how to start this.

    Basically, I'm trying to isolate x on one side, so that I can input f(x) and solve for x, instead of the other way around.

    Image: http://img146.imageshack.us/img146/8869/tempng8.png
  2. jcsd
  3. Sep 22, 2008 #2
    don't think that is possible
  4. Sep 22, 2008 #3
    Why would you ever want to invert such a useless function?

    If it's homework and you're having trouble solving for x in terms of f(x), then there's a good chance the function is not one-to-one and thus has no inverse. The way you would prove this, though, is to find two values, x and y, such that f(x) = f(y). Alternatively, if you can plot the graph of the function, you can use a horizontal line test to see if it's one-to-one. If you can find a horizontal line that passes through two distinct points on the graph, then you can't invert it.
  5. Sep 22, 2008 #4


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    Alternatively, if you just want the answer for yourself, you should consider numerical methods instead of analytic solutions.
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