3. The Gottahavit device is introduced in a market with 150 million potential buyers. The unit sales are modeled by the function s given by s(x) = -0.0131 x3 + 0.661 x3 - 2.021 x + 6.865 Where s is the total sales, in millions of units, x months after the device was released. a. Find the point of inflection, and interpret the meaning in terms of the rate of change in sales. b. Graph y = s(x) for 0