This is from a an AP Calculus BC 2006 exam.

http://img83.imageshack.us/img83/1067/setup.png

http://img13.imageshack.us/img13/3433/questionl.png

The answer is

http://img134.imageshack.us/img134/6788/answer.png

My question is, why start at t = 2? Why add the initial value?

I wrote my improper integral from 0 to infinity.