Question

the rate of change of the altitude of a hot air balloon is given by r(t)= t^3-4t^2+6 for [1,8] what expression gives the change in altitude of the balloon during the time the altitude is decreasing?

Answer 1

please and thank you :)

Answer 2

oh and it says the answer should be in definite integral form

Answer 3

altitude decreasing means the rate of change is negative, so your first job is to fine where it is zero. this however is not that easy, since you have a cubic equation.

Answer 4

also notice that the balloon is rising, the falling, then rising again. even on the interval [1,8]
so the question is rather confusing
http://www.wolframalpha.com/input/?i=+t^3-4t^2%2B6

Answer 5

ok then.. thank you :)