4/16 Q-Writing Exponential Functions

A tennis tournament begins with 128 players. At the end of round one, there will be 64 players. There are 32 players at the end of round 2 and 16 players remaining after round 3. Write the equation that best models this situation.

• y = -64x + 128

• y = 0.5x + 128

• y = 128(0.5)^x

• y = 128(2)^x

What is the a-value (or y-intercept) for the function: f(x) = 800(0.85)^x?

• 800

• 0.85

• 0.15

• x

The population of a city starts at 5,000 people and doubles every 3 years. What is the population after 9 years?

• 10,000

• 20,000

• 40,000

• 80,000

For each of the following problems, solve for the missing variable. Show all your work. 3. A bacteria culture starts with 1,000 bacteria and triples every 4 hours. Write the equation for the bacteria population and find the population after 12 hours. Equation: Population after 12 hours:

• Population after 12 hours: 27,000

• Population after 12 hours: 9,000

• Population after 12 hours: 81,000

• Population after 12 hours: 3,000

What is the equation of this table?

• y=512(1/4)^x
• y=32(4)^x
• y=32(1/4)^x
• y=512(4)^x

Write the exponential regression equation for the data.

• Y=8.16(2.7)^x

• Y=81.6(2.7)^x

• Y=8.16(.27)^x

• Y=8.16(27)^x

Write the equation that represents the table below:

• y=½(4)^x
• y=2(4)^x
• y=4(2)^x
• y=4(½)^x

Which of the equations below represent this table?

• y=3⋅(36)^x
• y=36⋅(3)^x
• y=3⋅(⅓)^x
• y=36⋅(⅓)^x