MATH 117 APPENDIX F

212x11

A. It opens down because the co efficient a -0.2 of x2 is negative.

B. The sales will increase; reach a peak, and then decrease to zero.

C. Set 212x11 0 and solve for x.

vertex x -b/2a -12/2(-0.2) 30

f(30) 191

D. solve this equation, we got x 60.9 and x-1. We disregard x-1.

So the last day ticket sold is about 61st day or 60 days after days after on sale day x1. The parabola opens down, so that means there will be a maximum.

E. Find the vertex of the parabola. The x-coordinate represents when the peak will occur. After 30 days or 29 days after x1.

F. The y-coordinate of the vertex represents how many tickets will be sold on the day of the peak. y191 tickets.

G. Answered in parts e and f. The vertex is at: (30,191)

The...