The Function f(x) is an Increasing Function in The Interval :

Consider the function
f (x) = -2x³ – 9x² – 12x + 1

1. The function f(x) is an increasing function in the interval
   (a) (-2, -1)                  (b) (-¥, -2)                          (c) (-1, 2)                              (d) (-1, ¥)
2. The function f(x`) is a decreasing function in the interval
   (a) (-2, -1)                  (b) (-¥, -2) only                (c) (-1, ¥)                            (d) (-¥, -2) È (-1, ¥)