Answer the following questions for the function
defined on the interval [−20,16].
a.) Enter the x-coordinates of the vertical asymptotes of f(x) as a comma-separated list. That is, if there is just one value, give it; if there are more than one, enter them seperated commas; and if there are none, enter NONE .
b.) f(x) is concave up on the region .
c.) Enter the x-coordinates of the inflection point(s) for this function as a comma-separated list.