Exam 3 V2 - Answer Key.pdf - Math 126 - EXAM 3 Version 2...

Math 126 - EXAM 3
Version 2
Name: Section: Date:
INSTRUCTIONS: Write your solutions clearly and concisely, and indicate all final answers.
Show all applicable work.
Honor Statement: I understand that cheating is a violation of the course policy as well as TMCC’s
academic conduct policy. If I am caught cheating, attempting to cheat, or assisting in the cheating
of another student, I understand that I will receive a failing grade in the course. I accept these
consequences as well as any other consequences that may follow outside of TMCC.
Sign:
Questions Points Score
1 10
2 6
3 10
4 10
5 10
6 6
7 10
8 6
9 8
10 10
11 6
12 8
Total: 100
1

1. (10 points) A radioactive substance decays in such a way that the amount of mass remaining
after t days is given by the function
m ( t ) = 12 e
− 0 . 014 t
where m ( t ) is measured in kilograms.
a. Find the mass at time t = 0.
kg
b. How much of the mass remains after 49 days?
kg
2. (6 points) Use the definition of the logarithmic function to find x . (Simplify your answer
completely and show all work for full credit. )
a. log
3
( x ) = 4.
x =
b. log
10
(0 . 001) = x
x =