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Homework Help: A weird domain and range? anybody up for a challenge

  1. Apr 3, 2005 #1
    A weird domain and range???? anybody up for a challenge

    y=x^2-2x+1 / x^2-x-2

    try it on the gfx calculator and check if this domain and range is right

    i wrote

    Domain ( -infinity, -1 ) union (-1,2) union ( 2, infinity)

    range (-infity, 0) union (-1 to infity)

    is there an easier way to write the domain and range instead of this format thats assuming this is even right heh please englighten me thanks
  2. jcsd
  3. Apr 3, 2005 #2
    Is that a typo on your range?
  4. Apr 3, 2005 #3
    Domain is correct, you can rewrite it as [itex]\{ x \in \mathbb{R} \ | \ 2 \neq x \neq -1\}[/itex] if you want.

    Range is harder... you're going to need to differentiate it to see where it has minima. I get

    [tex] \biggr\{ y \in \mathbb{R} \ \biggr| \ y \leq 0 \ \mbox{or} \ y \geq \frac{8}{9}\biggr\}[/tex]
    Last edited: Apr 3, 2005
  5. Apr 4, 2005 #4


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    It is correct.The function doesn't have values in the domain [itex] \left(0,\frac{8}{9}\right) [/itex]

    [itex] \mathcal{R}\left( y\right)=\mathbb{R}\diagdown \left(0,\frac{8}{9}\right) [/tex]

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