# Math 112 Solutions for 3.5, p. 269

3.
5.
The demand function is and the revenue function is , whose maximum occurs at ; the demand at that price is 640.
7.
(a) . (b) . (c) .
10.
(a) , . (b) . (c) . (d) (e) .
12.
Let be the number of times to order per year. Then the lot size is , the number on hand averages , and the inventory cost is whose minimum is at . Thus orders should be placed 6 times per year, with lot size 60.
14.
Line has equation , so has intercept . Since line has slope , line has slope and equation . Hence on when Now , so , so . Hence

15.
(a) .
17.
.

Jason Grout 2003-03-03