Question:
Write the domain and the range of the function, $f(x)=\frac{a x+b}{b x-a}$
Solution:
(i) domain
$f(x)=\frac{a x+b}{b x-a}$
As f(x) is a polynomial function whose domain is R except for the points where the denominator becomes 0.
Hence $x \neq b$
Domain is $\mathrm{R}-\{\underline{b}\}$
(ii) Range
Let $\mathrm{y}=\frac{a x+b}{b x-a}$
$Y(b x-a)=a x+b$
byx $-a y=a x+b$
byx $-a x=a y+b$
$x(b y-a)=a y+b$
x =$\frac{a y+b}{b y-a}$
x is not defined when denominator is zero.
by $-a \neq 0$
y≠a/b
Range is R-{a/b}.