What is the set of all points at which $f(x) = \frac{x + 1}{x^{2} - 5x + 6}$ is continuous?

Explanation

1. 01

   A rational function is continuous at every point where its denominator is not 0.

2. 02

   $x^{2} - 5x + 6 = (x - 2)(x - 3)$ is 0 only at $x = 2$ and $x = 3$, so $f$ is continuous on $\mathbb{R} - \{2, 3\}$.