Concept Test

1
Concept Test

• A jogger runs away from campus at a steady rate,
  stops to talk to some friends, runs away from
  campus for a little longer, and then returns to
  campus. Which graph below could show the
  joggers distance as a function of time?

2
Concept Test

• Suppose the average rate of change of jobs in
  Caddo Parish with respect to time is 10,000
  jobs/year for the period from 1995 to 2005. Which
  statement is most accurate?
• Each year, the number of jobs increased by
  10,000.
• The number of jobs never decreased.
• Both A) and B)
• Neither A) nor B)

3
Concept Test Which slope is largest?
4
Concept Test

• Given the graph on the right of y f(x), which
  of the below numbers is most positive?
• A f(2) f(0)
• B the average rate of change of f from x 0 to
  x 2
• C the average rate of change from x -2 to x
  0

5
Concept Test

• All four linear functions below are graphed on
  the right. Which one is the red line?
• A y 4 x
• B y 4 2x
• C y 2 2x
• D y 2 4x

6
Interpretation

• Three cars have the following functions that give
  the total cost of ownership as a function of the
  number of miles traveled
• Car A y 15,000 .14 n
• Car B y 28,000 .20 n
• Car C y 22,000 .09 n
• Which car was most expensive to purchase?
• Which car is the cheapest to operate per mile?
• After 60,000 miles, which car has had the lowest
  cost of ownership?

7
Concept Test

• (Multiple answers possible) Which of the below
  tables shows a linear function?
• D None of the above

8
Concept Test

• For which functions is y not directly
  proportional to x?
• For which functions is y not a linear function of
  x?

9
Concept Test

• You have been offered three different jobs job R
  has a base salary of 55,000 with annual raises
  of 2000, job S has a base salary of 45,000 with
  annual raises of 3200, and job T has a base
  salary of 48,000 with annual raises of 2000.
  Assuming you will be working at this job for many
  years, how should you rank the jobs according to
  the income you will receive?
• A) R, S, T B) S, R, T
• C) R, T, S D) None of the above

10
Concept Test

• Given two linear equations, how many solutions
  can the system have?
• A) Exactly one solution or no solution
• B) Exactly one solution or infinitely many
  solutions
• C) Exactly one solution, no solutions, or
  infinitely many solutions
• D) Any number of solutions

11
Concept Test

• The graph on the right shows three different tax
  systems as a function of income. Which
  represents a progressive tax (that is, where
  richer people pay a higher percentage of their
  income on taxes)?

12
Concept Test

• Which statement below is correct?
• A (-3x2)3 -3(x2)3 -3x6
• B (-3x2)3 -(3x2)3 -27x6
• C (-3x2)3 (-3)3(x2)3 -27x5
• D None of the above

13
Concept Test

• On your logarithmic scale of time, where does 500
  years ago fit?
• A closer to the 102 mark than to the 103 mark
• B closer to the 103 mark than to the 102 mark
• C exactly between the 102 and the 103 mark

14
Concept Test
Which of the following is true? A f(x) is
exponential and g(x) is linear B f(x) is neither
linear or exponential C g(x) is neither linear
or exponential D f(x) is linear and g(x) is
exponential
15
Concept Test

• A population of bacteria is described by y
  200(2.75)t where t is measured in days. Which
  statement is correct?
• A The population is growing at 75 per day.
• B The population is growing at 275 per day.
• C The population is growing at 175 per hour.
• D None of the above.

16
Concept Test

• If all functions below are graphed, which graph
  is the blue graph?
• y 200(.5)x
• y 200(1.1)x
• y 100(1.5)x
• y 200(.2)x

17
Concept Test

• Which of the below functions has a half life of 8
  days? (In all functions, t measures days.)
• A y 100(1/8)t
• B y 25(8)t
• C y 30(1/2)t/8
• D y 8(1/2)8t

18
Concept Test

• What will the half-life be for the equation y
  50(.5)4t where t is measured in days?
• .25 days
• 4 days
• 50 days
• None of the above

19
Concept Test

• If you know that log a is about .301, which of
  the following statements is true?
• A log(100a) is about 2.301
• B log(a2) is about .090601
• C Both A and B are true
• D Neither A nor B are true

20
Concept Test

• Suppose you know that ln(a) equals .25. What can
  you say about ln(ae4)?
• A It equals 4.25.
• B It equals .25 e4
• C It equals .254.
• D None of the above.