Growth & Decay Rate of Exponential Functions

Consider the exponential function  $f\left(x\right)=75\left(1.23\right)^x,$  which models Rita's savings account, where x represents the number of years since the money was invested. Is the money growing or decaying?

• Growing

• Decaying

Consider the exponential function  $f\left(x\right)=75\left(1.23\right)^x,$  which models Rita's savings account, where x represents the number of years since the money was invested. What is the rate of the growth or decay?

• -23%

• 23%

• 123%

• 223%

Consider the exponential function  $f\left(x\right)=75\left(1.23\right)^x,$  which models Rita's savings account, where x represents the number of years since the money was invested. What does the value of 75 represent?

• the rate of which the money is changing

• the initial amount invested

Consider the exponential function  $f\left(x\right)=75\left(1.23\right)^x,$  which models Rita's savings account, where x represents the number of years since the money was invested. What is the amount of money in Rita's savings account after 5 years?

• $375

• $461.25

• $211.15

The exponential function  $f\left(x\right)=33\left(0.4\right)^x,$  models growth or decay?

• exponential growth

• exponential decay

Consider the exponential function  $f\left(x\right)=33\left(0.4\right)^x,$  what is the rate of decay?

• 160%

• 40%

• 60%

Write an exponential function to represent a situation in which the initial value is 22 and the rate of decay is 13%?

• $f\left(x\right)=22\left(.87\right)^x$

• $f\left(x\right)=22\left(.13\right)^x$

• $f\left(x\right)=.87\left(22\right)^x$

• $f\left(x\right)=.13\left(22\right)^x$

The function  $f\left(x\right)=100\cdot1.20^x$  models that amount of money in Matt's savings account, where x represents the number of months since Matt first placed his money into his account. Which of the following are true statements? Select all that apply.

• The function models exponential decay.

• 100 represents that amount of money Matt put in his savings account in the beginning.

• The rate of growth is 20%

• Matt has $150 after the first month of his savings account.

• At the end of 8 months, Matt will have more than $500 in savings.

In an exponential function, what does the 'a' represent? 

• SLOPE
• RATE OF CHANGE
• Y-INTERCEPT
• COMMON RATIO

What is b, the common ratio, for the function: f(x) = 300(1.16)^x?

• 300
• 1.16
• .16
• x