# A weird domain and range? anybody up for a challenge

1. Apr 3, 2005

### dagg3r

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. Apr 3, 2005

### Jameson

Is that a typo on your range?

3. Apr 3, 2005

### Data

Domain is correct, you can rewrite it as $\{ x \in \mathbb{R} \ | \ 2 \neq x \neq -1\}$ if you want.

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

$$\biggr\{ y \in \mathbb{R} \ \biggr| \ y \leq 0 \ \mbox{or} \ y \geq \frac{8}{9}\biggr\}$$

Last edited: Apr 3, 2005
4. Apr 4, 2005

### dextercioby

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

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

Daniel.