Unit 9 Review

• There were originally 98 birds in the park

• The number of birds decreases by 3 every year

• The number of birds doubles each year

• The number of birds increase by a factor of 1.7 every year

•  5280

•  1400

•  .94

• 7000 

• 50

• 1

• 0.12

• x

• all real numbers

• all real numbers

• all imaginary numbers

• x < 0

• x > 0

• 4.5, 2.5, 0.5, -2.5, -4.5

• 4.5, 2.5, 0, -2.5, -4.5

• -4.5, -2.5, 0.5, 2.5, 4.5

• 4.5, -4.5, 4.5, -4.5, 4.5

A sequence is described by the function below.

Which of these is the correct formula?

A chemist has a 100-gram sample of a radioactive material.  He records the amount of radioactive material every week for 6 weeks and obtains the following data: Find the exponential model of the function.

• y = 100(8.7)^x
• y = 100(1.87)^x
• y = 100(.87)^x
• y = 100(.13)^x