Algebra2 6-1 Key Features of Exponential Functions

A factory purchased a 3D printer in 2010. The value of the printer is modeled by the function f(x)=30(0.93)^x , where x is the number of years since 2010.

a. what is the value of the printer in 10 years?

• $15.31

• $18.76

• $14.52

• $11.98

• none of the above

b. Does the printer lose more of its value ?

• the first 10 years

• the second 10 years

• the 3^rd 10 years

• none of the above

Two-hundred twenty hawks were released into a region on January 2, 2016. The function f(x) = 220(1.05)^x can be used to model the number of hawks in the region x years after 2016.

a. Is the population increasing or decreasing? Explain.

• a. decreasing; the base is greater than 1 so the function decreases as x increases

• b. increasing; the base is greater than 1 so the function increases as x increases

• c. decreasing; the base is greater than 1 so the function decreases as x decreases

• none of the above

Tags

CCSS.HSF.LE.B.5

b. In what year will the number of hawks reach 280?

• a. the number of hawks will reach 280 near the end of 2025

• b. the number of hawks will reach 280 near the end of 2031

• c. the number of hawks will reach 280 near the end of 2020

• d. none of the above

Tags

CCSS.HSF.LE.B.5

The exponential function f(x) = 2500(0.4)^x models the amount of money in Zachary's savings account over the last 10 years. Is Zachary's account balance increasing or decreasing? Write the base in terms of the rate of growth or decay.

• a. increasing; 2.0 – 2.21

• b. increasing; 0.6 – 1.0

• c. decreasing; 0.8 – 0.6

• d. decreasing; 1 – 0.6

• e. none of the above

Tags

CCSS.HSF.LE.B.5

Use the structure. What value of a completes the equation y = a.2^x for the exponential growth function shown?

• a. 1.5

• b. 2.0

• c. 2.8

• d. 4

• e. none of the above

Tags

CCSS.HSF.LE.A.2

Error Analysis. Describe and correct the error a student made in identifying the growth or decay factor for the function y = 2.55(0.7)^x.

• a. The rate is 0.4, so the decay factor is 0.89

• b. The rate is 0.25, so the decay factor is 0.659

• c. The rate is 0.30, so the decay factor is 0.8

• d. The rate is 0.30, so the decay factor is 0.70

• e. none of the above

Tags

CCSS.HSF-IF.C.8B