1. Let f (x) = x - 4, g (x) = x- - 4, and h (x) = Vx - 0.5 find the function and state its domain. 2. Use the definition of the derivative (also called the 4-step process) to find the derivative of f (x) = x+6 2x 3. The monthly variable cost function of Company A is given by V (x) = -x (x - 6) dollars for x units. a) Find the average rate of change of the variable cost with respect to x in the interval from x = 5 to x = 5.1. b) Find the rate of change of the variable cost at x = 5