Answer the following questions for the function defined on the interval [-15, 17]. 3 f(x) x = x² - 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 separated commas; and if there are none, enter NONE. Answer: -4, 4 b.) f(x) is concave up on the region (-4,0) U (4,00) Note: Give your answer in interval notation. c.) Enter the x-coordinates of the inflection point(s) for this function as a comma-separated list. Answer: 0