Question

help with calculus question...

Answer 1

http://apcentral.collegeboard.com/apc/public/repository/ap08_calculus_ab_q2.pdf

Answer 2

its part c. I don't understand it.

Answer 3

the website gives the answer. I just don't get it. :(

Answer 4

count the number of increases and decreases

Answer 5

from 0, 1, 2 it is increasing, then at 4 it is less
that is one

Answer 6

sorry i meant 0, 1, 3 but same idea

Answer 7

then from 4 to 7 it goes up again
that is two

Answer 8

then from 7 to 8 it goes down
that is 3

Answer 9

there is an explanation given there, but it is rather stupid
what is even more stupid is the idea of ticket sales, which is evidently a step function (tickets are sold in discrete units) can be differentiable and have a derivative with zeros

Answer 10

so it increases on (0,3) and (4,7) and decreases on (3,4) and (7,9), or (7,8)?

Answer 11

basically
on (0,3) it is increasing
on (3,4) decreasing
on (4,7) increasing and
on (7,9) deceasing

Answer 12

changes 3 times, gives 3 zeros for the derivative

Answer 13

oh ok thanks. I think i got it now.

Answer 14

then we come to part D which gives you \(L'=5000te^{-\frac{t}{2}}\) and this only has ONE zero, namely at \(t=2\)
what a weird question
i wonder who wrote it

Answer 15

oh actually it has only one zero at \(t=0\) but it is still wrong!

Answer 16

oh don't worry, i only needed part c. Thanks! :)

Answer 17

yw