Question:
Write the domain and range of the function $f(x)=\frac{x-2}{2-x}$.
Solution:
Given:
$f(x)=\frac{x-2}{2-x}$
Domain ( f ) :
Clearly, f (x) is defined for all x satisfying: if 2
Hence, domain ( f ) = R
Range of f :
Let f (x) = y
$\Rightarrow \frac{x-2}{2-x}=y$
$\Rightarrow x-2=y(2-x)$
$\Rightarrow x-2=-y(x-2)$
$\Rightarrow y=-1$
Hence, range $(f)=\{-1\} .$