The domain of the function $f(x) = \sqrt { - x^2 + 8 x - 15 }$ consists of one or more of the following intervals: $(-\infty, A]$, $[A, B]$ and $[B, \infty)$ where $A < B$.
Find $A$
Find $B$
For each interval, answer YES or NO to whether the interval is included in the solution.
$(-\infty, A]$
$[A, B]$
$[B,\infty)$