MATH QUIZ 6
IN ORDER TO GET FULL CREDIT FOR EACH PROBLEM, PLEASE SHOW ALL WORK AND WRITE EVERYTHING OUT CORRECTLY USING THE LANGUAGE OF MATH.
The quiz is worth 100 points. Each problem is worth 5 points.
1. Determine whether each of the following graphs represents a one-to-one
function.
(a)
(b)
(c)
(d)
2. For each part below, determine if an inverse for the given f( x )
exists. If an inverse exists, then please find the inverse.
Otherwise, write “NO INVERSE”.
(a) f( x ) = 3x + 3
(c) f( x ) = 7
(d) f( x ) = 5x2 + 4x
3. In order to check to make sure we have the right inverse for a
make sure that the inverse you got in #2 (a) is the correct inverse
for f( x ) = 3x + 3.
4. The following formula can be used to convert Fahrenheit temperatures
x to Celsius temperatures T(x):
a) Find T(-13) and T(86).
b) Find T-1(x) and explain what it represents.
5. Please choose which equation represents the following graph:
A. f( x ) = -ex
B. f( x ) = -ex + 1
C. f( x ) = e-x + 1
D. f( x ) = ex – 1
6. Please choose which equation represents the following graph:
A. f( x ) = 2x - 1
B. f( x ) = 2x - 1
C. f( x ) = -2x - 1
D. f( x ) = -2x - 1
7. Water initially at 130 degrees Fahrenheit is left in a room of temperature
70 degrees Fahrenheit to cool. After t minutes, the temperature T of the
water is given by
Find the temperature of the water 10 minutes after it is left to cool.
8. Suppose that $100,000 is invested at 4% interest, compounded
monthly. Find the amount of money in the account after 10 years.
9. Find each of the following, and round answer to the nearest 4 decimal places.
(a) e4
(b) e-2
(c) log 50
(d) log2 128
(e) ln 50
10. Find log4 50 using the change of base formula, and round answer to the
nearest 4 decimal places.
11. Students in an accounting class took a final exam and then took equivalent
forms of the exam at monthly intervals thereafter. The average score
S(t), as a percent, after t months was found to be given by the function
S(t) = 78 – 15 log(t + 1)
(a) What was the average score when the students initially took the
test?
(b) What was the average score after 4 months? after 24 months?
12. Express log 2x as a sum of logarithms.
FOR #15 AND #16, EXPRESS IN TERMS OF SUMS AND DIFFERENCES
OF LOGARITHMS.
FOR #17 AND #18, EXPRESS AS A SINGLE LOGARITHM, AND IF POSSIBLE, SIMPLIFY.
17. ln 44 – ln 4