hoose the best answer from the given choices: 1. The points at which the tangents to the curve y = x2 - 12x +18 are parallel to x-axis a (a) (2, - 2), (- 2, -34) (b) (2, 34), (- 2, 0) (c) (0, 34), (-2, 0) (d) (2, 2), (-2, 34). 2. The interval on which the function f (x) = 2x3 + 9x2 + 12x - 1 is decreasing is (a) [-1, 0o] (b) [-2, -1] (c) [-00, -2] (d) [-1, 1] 3. Which of the following functions is decreasing on (0, 12)? (a) sin 2x (b) tan x (c) cos X (d) cos 3x