Free response · Unit 4 Beta

Medicine in the blood: rates from data and from a model

Rate in context from a table · Part A: graphing calculator allowed · 9 points

The question

Name: ______________________   Date: ____________   Medicine in the blood: rates from data and from a model (9 points)

Table

Concentration of a medicine

The concentration of a medicine in a patient's blood is modeled by a differentiable function CC, where C(t)C(t) is measured in milligrams per liter (mg/L) and tt is measured in hours after the medicine is taken. Selected values of C(t)C(t) are shown in the table.
Concentration C(t), in milligrams per liter, at selected times t, in hours
tt (hours)001133446688
C(t)C(t) (mg/L)007.47.412.212.212.012.09.99.97.37.3
  1. (a) Use the data in the table to estimate C′(5)C'(5). Show the computations that lead to your answer, and indicate units of measure. [2 points]

  2. (b) Interpret the meaning of C′(5)≈−1.05C'(5) \approx -1.05 in the context of the problem. [1 point]

  3. (c) Must there be a time tt, for 1<t<31 < t < 3, at which C(t)=10C(t) = 10? Justify your answer. [2 points]

  4. (d) For 0≤t≤80 \le t \le 8, the concentration is also modeled by M(t)=10te−0.3tM(t) = 10te^{-0.3t}. Find M′(5)M'(5). Show the setup, and indicate units of measure. [2 points]

  5. (e) Using the model MM, is the rate of change of the concentration increasing or decreasing at t=6t = 6? Give a reason for your answer. [2 points]