# What is the domain and range of f(x)=(x-2)/(x^2-6x+9)?

Jan 23, 2017

The domain of $= \mathbb{R} - \left\{3\right\}$
The range of $= \mathbb{R}$

#### Explanation:

Let's factorise the denominator

${x}^{2} - 6 x + 9 = {\left(x - 3\right)}^{2}$

As you cannot divide by $0$, $x \ne 3$

The domain of $f \left(x\right)$ is ${D}_{f} \left(x\right) = \mathbb{R} - \left\{3\right\}$

${\lim}_{x \to - \infty} f \left(x\right) = {\lim}_{x \to - \infty} \frac{x}{x} ^ 2 = {\lim}_{x \to - \infty} \frac{1}{x} = {0}^{-}$

${\lim}_{x \to + \infty} f \left(x\right) = {\lim}_{x \to + \infty} \frac{x}{x} ^ 2 = {\lim}_{x \to + \infty} \frac{1}{x} = {0}^{+}$

$f \left(0\right) = - \frac{2}{9}$