How many critical values does the function f(x) = 3x^4 + 4x^3 have? none one two three four the function y = x^3 + 15 x^2 - 33 x has a relative maximum when x = -11. 11. 0. -1. 1. the function f(x) = 4x^3 - 10x^2 - 8x + 3 is decreasing on (-infinity, 2). (-1/3, infinity). (-1/3, 2). (2, infinity). (-infinity, 1/3).