Sunday
April 20, 2014

Homework Help: Pre-Calculus

Posted by Stacy on Saturday, November 19, 2011 at 4:18pm.

This is application question.
Bacterial Control. If t days after treatment the bacteria count per cubic centimeter in a body of water is given by C(t) = 10t^2 - 120x + 800
0 <= t <= 9
Thn in how many days will the jcount be a minimum?

I got this result:

20(t^2 - 6 + 40)
20(t - 5)(t - 8)
t - 5 = 0 t - 8 = 0
t = 5 t = 8
f(5) = 700
f(8) = 1120
f(0) = 800
f(9) = 1340

20(3)^2-120(3)+800
500-600+800 = 700

20(8)^2-120(8)+800
1280-960+800 = 1120

20(0)^2-120(0)+800 = 800

20(9)^2-120(9)+800 =1340

minimum = 700

but this is incorrect. What am I doing wrong and how do I solve it?

Answer this Question

First Name:
School Subject:
Answer:

Related Questions

math/Calculus - A bacterial population starts at 500 and doubles every four days...
math - A certain antibioyic reducesthe number of bacteria in your body by 10% ...
Pre-Calculus/Calculus - I am too embarassed to ask this Calculus (really pre-...
Pre Calculus - Pre Calculus why is sin(-20)/cos 380 equal to tan (-200)
Question about college application - I had submitted a college application essay...
calculus - Bacterial Population: A bacterial colony is estimated to have a ...
Pre-Calculus - One model for the population P of bacteria in a sample after t ...
Statistics - According to a study by the Centers for Disease Control, the ...
College Application - I am filling out a college application to a university in ...
PreCalculus - 2000(1 0.75) = 2000 (.25) = 500 survivors after the dose of ...

Search
Members