Exponential Functions

What is it about the equation y = 2(9/7)^x that indicates that it is a model for exponential growth?

• The equation is growth because 2 is positive.

• The equation is growth because the factor is positive.

• The equation is growth because the factor is greater than one.

• The equation is growth because the exponent is always positive.

Consider the equation y=200(1.08)^x which models the increase in value of an autographed Annie program. Let y = the value of the item, let x = the number of years since the performance. What does the 1.08 in the equation indicate?

• The value of the item is increasing by $1.08 each year.

• The value of the item is increasing by 1.08% each year.

• The value of the item will increase to $200 1.08 years after purchase.

• The value of the item is increasing by 8% each year.

What is an asymptote?

• A special bag used by hikers and athletes to carry valuables.

• an imaginary vertical line that helps define the reflection of a graph.

• an imaginary horizontal line that helps define where the graph will approach, but never reach.

• another term for vertical intercept.

What is a, the starting term, for the function: f(x) = 300(1.16)^x?

• 300
• 1.16
• .16
• x

The value of a car is $15,000 and depreciates at a rate of 8% per year. What is the decay factor?

• ^.08
• ^1.08
• .92
• 8

Which of the following functions shows an initial amount of $15 and an increase of 35% each year?

• y = 15(35)^x
• y = 15(1.35)^x
• y = 15(0.35)^x
• y = 35(1.15)^x

Classify the model as Exponential GROWTH or DECAY.
A=1200(.85)⁶

• Growth
• Decay

Classify the model as Exponential GROWTH or DECAY.
A=10(1.01)³

• Growth
• Decay

Is the pictured graph growth, decay, or linear or none?  

• Exponential Growth
• Exponential Decay
• Linear
• None

Suppose a culture of bacteria begins with 5000 cells and dies by 30% each year. Write an equation that represents this situation.

• y=5000(0.7)^x
• y=30(5000)^x
• y=5000(1.3)^x
• y=5000x^x