Question:
Find the domain of the function $f(x)=\frac{x^{2}+2 x+1}{x^{2}-8 x+12}$
Solution:
The given function is $f(x)=\frac{x^{2}+2 x+1}{x^{2}-8 x+12}$
$f(x)=\frac{x^{2}+2 x+1}{x^{2}-8 x+12}=\frac{x^{2}+2 x+1}{(x-6)(x-2)}$
It can be seen that function f is defined for all real numbers except at x = 6 and x = 2.
Hence, the domain of $f$ is $\mathbf{R}-\{2,6\}$.