14. Which of the following statements is true? a) If f is differentiable, then a f(Vx) = ['() 2Vx tan x = - sec2 x c) If f'(x) = g'(x) for all x, then f (x) = g(x) d) If f (x) is increasing on [0,1], then If (x)12 is increasing on [0,1] 15. The area of a circle, A = 72 changes as its radius changes. If the radius changes with respect to time, the change in area with respect to time is a) constant A = 2nr - b) - dr at C) dr - = 2ur d) - = 2nr+ e) impossible to find 16. Select all true statements a) If f is differentiable on (-2, 2), then f is continuous at x = 1 b) For all functions f, if f(a) 0, then there must be a number c in the interval (a, b) such that f (c) = 0 c) All critical points of f (x) satisfy f'(x) = 0 d) If f (a) exists but f'(a) does not exist, then x = a is a critical point of f (x)