Question

:D
How do you remember rational expresssions

Answer 1

may not be, after simplifying, you may loose the domain information

Answer 2

let me cook up some nice example..

Answer 3

take this funciton :-

\(\large f(x) = \frac{x-1}{x^2-3x+2}\)

Answer 4

first, find its domain.

simplify the function, and independently find the domain of that simplified function also

Answer 5

you will get different domains, before simplification and after.
that should convince u that you lost the domain information by simplifying