Rosie receives a weekly salary of $350 and a 6% commission on all sales. a.) write a function f (d) that model the weekly earnings in terms of d dollars in sales.

b.) Find Rosie's earnings for a week with $670 total sales.

The average number of vehicles waiting in line to enter a parking lot can be modeled by the function f left parenthesis x right x squared over 2 left parenthesis 1 minus x right parenthesis endfraction , where x is a number between 0 and 1 known as the traffic intensity. find the rate of change of the number of vehicles waiting with respect to the traffic intensity for the intensities (a) xequals0.3 and (b) xequals0.6.