Results 1 to 2 of 2

Math Help - Reading a function

  1. #1
    Member
    Joined
    Aug 2007
    Posts
    96

    Reading a function

    okay, so i need to determine whether or not f is one-to-one and onto. if so, find f^-1.

    im pretty sure i can do it, i just dont know how to read the thing.

    A=R \ {0} and B=R \ {2} and f: A->B

    f(x)= 1/x + 2


    where R is the reals. can anyone please explain to me how to read that?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor red_dog's Avatar
    Joined
    Jun 2007
    From
    Medgidia, Romania
    Posts
    1,252
    Thanks
    5
    f:A\to B is bijective if and only if \forall y\in B, the equation f(x)=y has an unique solution x\in A

    Now, let y\in\mathbf{R}-\{2\}

    \displaystyle f(x)=y\Leftrightarrow \frac{1}{x}+2=y\Leftrightarrow \frac{1}{x}=y-2\Leftrightarrow x=\frac{1}{y-2}\in\mathbf{R}-\{0\}
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 8
    Last Post: September 20th 2011, 01:42 PM
  2. uncertainty in a reading
    Posted in the Math Topics Forum
    Replies: 0
    Last Post: February 15th 2011, 09:04 PM
  3. help reading maple PLEASE
    Posted in the Math Software Forum
    Replies: 0
    Last Post: December 14th 2010, 11:05 AM
  4. Am I Reading Too Much Into This?
    Posted in the Calculus Forum
    Replies: 4
    Last Post: July 9th 2008, 10:26 PM
  5. Help reading notation
    Posted in the Advanced Algebra Forum
    Replies: 1
    Last Post: February 8th 2008, 09:22 AM

Search Tags


/mathhelpforum @mathhelpforum