The domain of the function f(x)=(x^2+1)/(x^2-3 x+2) is

The correct answer is Option (3) → $R-\{1,2\}$

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

$x^2-3 x+2⇒x^2-2x-x+2$

$⇒x(x-2)-1(x-2)$

$⇒(x-1)(x-2)$

$⇒f(x)=\frac{x^2+1}{(x-1)(x-2)}$

so $x≠1,2$

so domain = $R-\{1,2\}$