Applications of differentiation-word problem

[abby_07]

I have no idean how to approach this problem can you please help?

The concetration C of a certain chemical in the bloodstream t hours after injection muscle tissue is given by

c=3t/27+t^3

when is the concentration greatest?

i know i have not worked anything out but i dont know what to do

 

[skeeter]

this is just an optimization problem ...

find dC/dt, set it equal to 0, and find your critical value(s). note that your domain is t > 0.

use the first derivative test to analyze the function C and locate the maximum.

you should get the max at t = (27/2)^(1/3) hrs