please I need help answering these questions

Given fx) = 2x - 3x2 - 36x - 10. (a) Find the intervals on which f is increasing or decreasing. (b) Find the relative maxima and relative minima of f. (a) Increasing on (-60, -2) and (3, co), decreasing on (-2. 3) (b) Rel. max. /(-2) = 34, rel. min. /(3) = -91 (a) Increasing on (-co, -3) and (2, co), decreasing on (-3. 2) b) Rel. max. /(-3) = 17. rel. min. /(2) = -78 (a) Increasing on (-3, 2), decreasing on (-co, -3) rad (2, co) (b) Rel. max. /(2) = 78. rel. min. /(-3) = -17 (a) Increasing on (-2, 3), decreasing on (-co, -2) and (3, co) (b) Rcl. max. /(3) = 91. rel. min. /( 2) = -34Gravel is being dumped from a conveyor belt at a rate of 35 ft'/min and its coarseness is such that it forms a pile in the shape of a cone whose base diameter and height are always equal. How fast is the height of the pile increasing when the pile is 15 ft high? Round the result to the nearest hundredth. O 0.6 ft/min O 0.20 ft/min O 0.14 ft/min 0.27 ft/min 1.24 ft/min