18. The second derivative of a function f is f" (x) = 6x3(x2 - 2). Determine the interval(s) where the function f is concave up. [A] (-00, 0), (0, 00) [B] (-00, V2), (0, V2) (-V2,0), (V2, 0.) [D] (0, V2), (V2, 0.) [E] (-00, 00) 19. The functions f, g, and h are all continuous on the interval [a, b]. The table gives the sign of each function and its derivatives for the interval [a, b]. Use the table to match each function with its graph. f (x) > 0 g (x) > 0 h(x) > 0 f' (x) > 0 *g' (x ) > 0 h'(x) 0 g" (x) 0 II III X