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Math Help - Functions question.

  1. #1
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    Functions question.

    I really don't understand this question.

    If f(x) = 1/x, show that f(a) - f(b) = f(ab/(b-a))

    Help would be greatly appreciated
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  2. #2
    Super Member Failure's Avatar
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    Quote Originally Posted by Archelaus View Post
    I really don't understand this question.

    If f(x) = 1/x, show that f(a) - f(b) = f(ab/(b-a))

    Help would be greatly appreciated
    Just transform the right hand side of this equation to the right hand side, by applying the definition of f(x) and some quite routine algebraic transformations

    f(a)-f(b)=\frac{1}{a}-\frac{1}{b}=\ldots = \frac{1}{\frac{ab}{b-a}}=f\left(\frac{ab}{b-a}\right)

    and you are done.
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