Writing and interpreting exponential functions

• Time

• Decay or Growth Factor

• Starting Amount ( Y - int)

• Bomsta

A car's value is modeled by the equation

 $23000\left(.8\right)^t$  , where t is years. Which statement correctly interprets the equation?

• The price of the car was originally $8,000

• the price of the car is originally $23,000 and increases by 80% over time

• the price of the car is originally $23,000 and decreases by 80% over time

• the price of the car is originally $23,000 and decreases by 20% over time

The population of bacteria in a Petri dish is 550 and increases according to the expression $550\left(3.4\right)^{0.005t}$  

 , where t is the number of hours. 

What effect would increasing the initial population of the bacteria have on the rate at which the number of bacteria increases?

• An increase in the initial population will lower the rate at which the population increases.

• An increase in the initial population does not affect the rate at which the population increases. 

•  An increase in the initial population will increase the rate at which the population increases. 

• An increase in the initial population increases the time the bacteria are increasing.

P = 8(1.23)^t

What is the initial quantity?

 $y\ =\ 3,000\left(1.23\right)^{t\ }$  What is the inital amount? 

• 1.23

• .23

• .77

• 3,000

What is the initial amount, for the function:

f(x) = 300(1.16)^x

• 300

• 1.16

• 0.16

• 3

• 16%

What does the a in y=a(1+r)^x represent?

• Time

• Rate

• Slope

• Initial Amount

What is the initial value of this table?

• 4

• 5

• 20

• 3

• 
• 
• 
• 

 $y\ =\ 5\left(\frac{1}{3}\right)^x$  What's the y-intercept and does this show growth or decay?

• 5, growth

• 5, decay 

•  $\frac{1}{3}$  growth

•  $\frac{1}{3}$  decay