Official 2008 Calculus AB FRQ Discussion

TheMathProf
Sat, 10 May 2008 00:07:31 +0000

I would not add 120. The presence of a line for people waiting to buy tickets at time 0 does not mean that those people bought the tickets before time 0. They probably did buy tickets, but after time 0, and are already accounted for in the r(t) equation that is already provided. When we take the integral from 0 to 3 of r(t) dt, my claim is that those people in line at time t = 0 are already being counted, and therefore, adding 120 to the integral will double-count them.

Sheed30’s argument seemed to be that 120 tickets were already sold at time t = 0, and thus needed to be added to the accumulation, at least as I understand the argument. My counter to that is that the 120 people were merely in line, and thus had not yet purchased tickets, and that therefore there was no initial value of ticket sales that needed to be accounted for.