Below is the function $f(x)$.
Over which interval of $x$ values is $f' > 0$?
$\circ (4, \infty)$
$\circ [4, \infty)$
$\circ (-\infty, 4)$
$\circ (-\infty, 4]$
$\circ (-\infty, \infty)$
Over which interval of $x$ values is $f' < 0$?
$\circ (4, \infty)$
$\circ [4, \infty)$
$\circ (-\infty, 4)$
$\circ (-\infty, 4]$
$\circ (-\infty, \infty)$
Over the interval $(-\infty, \infty)$, this function is
$\circ$ concave up ($f'' > 0$)
$\circ$ concave down ($f'' < 0$)
