C. Determine whether the function is increasing or decreasing in the given interval. 1. f (x) = Vx; (1, 4) 2. f (x) = 6x - x3; (-1, 3] 3. f (x) = 6x + 3x7 - 4x3; [1,3] D. Find the value/s of x for which the curve of the given function has a point of inflection. 1.y= (x - 1)(x-6) 2. y = 3x4 - 4x3 + 1 3. y = 3x - 15x*+ 20x#+ 3