what is e? i dont know what it represents

1 pt) Sony BMG Music Corporation has found, based on data from the last 5 years of sales, that the following is a realistic model for profit, (in millions of dollars), as a function of volume of sales, (in millions of CD's) Your boss, CEO Rolf Schmidt-Holtz has to report to a board meeting on current sales and sales growth and ask you to give him the data in one-half hour. You note that the last quarter the sales totalled 2 million CD's. To estimate the instantaneous change of profit, when sales are at 2 million CD'syou compute the average rate of change for salesbeginning with 2 million CD's and going to (i) 3 million CD's (give answers to four decimal places and in dollars per CD)

(ii) 2.1 million CD's

(iii) 2.001 million CD's

Based on these calculations, when you report to your boss what is your best estimate for the instantaneous rate of change of profit when sales are 2 million CD's: dollars per CD.