Results 1 to 2 of 2

Thread: Functions question.

  1. #1
    Newbie
    Joined
    Jul 2010
    From
    Lárnaka, Cyprus
    Posts
    1

    Functions question.

    I really don't understand this question.

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

    Help would be greatly appreciated
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member Failure's Avatar
    Joined
    Jul 2009
    From
    Zürich
    Posts
    555
    Quote Originally Posted by Archelaus View Post
    I really don't understand this question.

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

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

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

    and you are done.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 6
    Last Post: Oct 17th 2009, 07:16 PM
  2. Question regarding functions
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: Sep 22nd 2009, 09:01 PM
  3. Question about functions...
    Posted in the Discrete Math Forum
    Replies: 2
    Last Post: Jan 25th 2009, 04:30 PM
  4. Question about functions
    Posted in the Algebra Forum
    Replies: 3
    Last Post: Oct 26th 2008, 06:35 PM
  5. Question about functions and a identity Question
    Posted in the Trigonometry Forum
    Replies: 2
    Last Post: Sep 8th 2008, 10:03 PM

Search Tags


/mathhelpforum @mathhelpforum