2. Determine the "positive" and "negative" intervals of the function g : (a) g(x) =-3x2 +4x ( b ) g(x) =4x3 -12x2 (c ) g(x) =4x3 -6x2 + 2x (d) g(x) = 4(x -4)2(x-1) (e) g(x) = 12(x -4)(x-2)