Question

The table below shows the functions to represent the sale f(t), in thousands, of four companies in t years: Company A B C D Sale f(t) = 1.05t f(t) = 0.75t f(t) = 1.212t f(t) = 0.9712t Which of the following companies showed an exponential growth in sale? Company A and Company C Company B and Company D Company C and Company D Company A and Company B Question 32(Multiple Choice Worth 1 points) (04.07) The amount of a radioactive material changes with time. The table below shows the amount of radioactive material f(t) left after time t: t(hours) 0 1 2 f(t) 180 90 45 Which exponential function best represents the relationship between f(t) and t? f(t) = 0.5(180)t f(t) = 180(0.25)t f(t) = 180(0.5)t f(t) = 0.5(50)t Question 33(Multiple Choice Worth 1 points) (04.03) The number of bacteria in a sample increased by a factor of 2 every minute from 9:05 a.m. to 9:55 a.m.. The function below shows the number of bacteria in the sample f(x) after x minutes from 9:05 a.m: f(x) = 10(2)x Which of the following is a reasonable domain for the function? 0 ≤ x ≤ 10 5 ≤ x ≤ 55 0 ≤ x ≤ 50 All positive integers

Answer 1

1) Company A and C

2)Your answer is f(t) = 180(0.5)^t This is because the number is cut in half for every hour.

3)C 0 ≤ x ≤ 50 is the right answer because the starting time 9:05 is considered as zero and the 9:55 is the ending point which is considered as 50.Or simply the difference of both the times is the domain of the function.