Modeling Functions

Rhonda deposited $3000 in an account in the Merrick National Bank, earning 4.2% interest, compounded annually. She made no deposits or withdrawals. Write an equation that can be used to find B, her account balance after t years.

• B(t) = 3000(1 - 4.2)^t

• B(t) = 3000(1 + 4.2)^t

• B(t) = 3000(1 - 0.042)^t

• B(t) = 3000(1 + 0.042)^t

Marilyn collects old dolls. She purchases a doll for $450. Research shows this doll's value will increase by 2.5% each year. Write an equation that determines the value, V, of the doll t years after purchase.

• V(t) = (1 + 0.025)^t

• V(t) = (1 - 0.025)^t

• V(t) = (1 + 2.5)^t

• V(t) = (1 - 2.5)^t

A car was purchased for $25,000. Research shows that the car has an average yearly depreciation rate of 18.5%. Create a function that will determine the value, V(t), of the car t years after purchase.

• V(t) = 25000(1 - 0.185)^t

• V(t) = 25000(1 + 0.185)^t

• V(t) = 25000(1 - 18.5)^t

• V(t) = 25000(1 + 18.5)^t

John invested $900 in a savings account at a 2.3% annual interest rate. He made no deposits or withdrawals on the account. Write a function J(t) to represent the amount of money in the account after t years.

• J(t) = 900(1 - 0.23)^t

• J(t) = 900(1 + 0.23)^t

• J(t) = 900(1 + 0.023)^t

• J(t) = 900(1 - 0.023)^t

HINT: Use your y= on the calculator to determine which one is equivalent.

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Write the equation of the exponential function for the given table. HINT: STAT EDIT STAT --> CALC #0

The bear population in a given area is currently 1580. They anticipate the bear population to decrease by 2% each year. Which function represents the population of bears, B, after t years.

• B = 1580(0.02)^t

• B = 1580(1 – 0.02)^t

• B = 1580(1 + 0.02)^t

• B = 1580(1 – 0.2)^t

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

• y = 15(1.035)^x

• y = 15(1.35)^x

• y = 15(0.35)^x

• y = 15(0.65)^x

What is the equation of the following table? HINT: Use your STAT Key on your calculator

• y = 7(2)^x

• y = 4x + 7

What is the equation of the following table? HINT: Use your STAT Key on your calculator

• y = 2x + 4

• y = 4(2)^x