Exponential Functions Quiz #1

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

Suppose you deposit $3000 in a savings account that pays interest at an annual rate of 4%. If no other money is added or withdrawn from the account, how much will be in the account after 10 years?

• $3122.18
• $4994.50
• $4440.73
• $86,776.40

A population of fish starts at 8,000 and decreases by 6% per year. What is the population of fish after 10 years?

• 14327
• 4309
• 839
• 7680

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

Riley invested $1,000 in savings bonds. If the bonds earn 6.75% interest compounded semi-annually, how much total will Riley earn in 15 years?

• $1,584.62
• $2,651.39
• $2,706.86
• $1,825.10

Olivia would like to buy some new furniture for her home. She decides to buy the furniture on credit with 9.5% interest compounded quarterly. If she spent $7,400, how much total will she have paid after 8 years.

• $15,415.94
• $15,683.28
• $15,927.56
• $16,109.05

Determine the horizontal asymptote for the function

f(x) = 3(2)^x-4 + 5

• x=4

• y=4

• x=5

• y=5

Given the original exponential function defined by y=4^x, how would the graph change if the function were:

y=2(4)^x-3+1?

• Vertically stretched by a factor of 2, right 3, and up 1

• Vertically compressed by a factor of 1/2, left 3 and down 1

• Vertically compressed by a factor of 1/2, right 3, and down 1

• Vertically stretched by a factor of 2, left 3, and up 1

Identify whether the following scenario represents exponential growth or decay: A population of bacteria doubles every hour.

• Exponential growth

• Exponential decay

• Linear growth

• Logarithmic growth

The expression 1350(1.05)^t models the average wages, in dollars, in the US as a function of the number of years since 1930. What does 1.05 represent in this expression?

• The average wages in the US were about $1.05 in 1930.

• The averages wages in the US increase by about 5% each year.

• The average wages double every 1.05 years.