Most forums try to discourage the bumping of topics (esp. after less than 2 hours), unless the OP has additional progress to post.
You will be more likely to get help if you take the time to type out your questions/work, preferably using as many who help simply don't want to download files. Just a bit of unsolicited advice.
In (b), the reduction would be a curve (not a line) . I replaced t with t-4 because the reduction period starts at t=4 hours.
For (c), they want to know the rate of increase of the area of the disc. The rate of increase of the radius of the disc is 0.5 cm/hour. So it's a related rates problem.
Everything else looked good.
Just google or do a search here for lots of information on using LaTeX. Once you get started, you'll find its fairly straightforward, and once you know most of the commands it is a breeze.
In looking over you work, I find:
a) You have correctly determined the growth period of 4 hours and the reduction period of 4 hours to get a total time of 8 hours for the experiment.
b) You want to graph:
c) Here you are asked how fast the area is growing just before the antibiotic is introduced, so begin with:
Now differentiate with respect to , then plug in to get the growth of the disk in .
e) This isn't correct.This should be done similarly to part c).
Here's what I came back with
(b) Table of values
Where I got a graph looking like this
Sub 4 for t
(e)I don't think this one is right
Thanks for the help, I know my LaTeX isn't the cleanest but I'll try to clean it up in the future. I think I'm starting to appreciate the time people spend typing up each function/equation using LaTeX. It really goes to show how generous they are.
Another BIG thanks!
edit: The graph didn't come out right, had to fix it, can't get rid of the 'Attachment 28305' though