(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

y = [tex]\frac{1}{(x-1)(x+2)}[/tex]

find out the domain and range

ans: y<= -4/9 or y>0

[tex]x~E~R~-\{-2,1\}[/tex]

3. The attempt at a solution

I know the solution and I used this methoD:

y(x^2 + x -2) =1 (where [tex]y\neq0[/tex] )

when x is real, the discriminant

y^2 -4y(-2y-1) >=0 (where [tex]y\neq0[/tex] )

9y^2 + 4y >= 0 (where [tex]y\neq0[/tex] )

y(9y +4) >= 0 (where [tex]y\neq0[/tex] )

y<= -4/9 or y>0

My request is ... plz use some other easy method to illustrate this problem.. I want to know other methods of solving this same problem.. plz help.

====================================================================

Forum $ignature: www.lingouist.blogspot.com[/URL]

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Find out domain and range

**Physics Forums | Science Articles, Homework Help, Discussion**