Benchmark 3 Review

Which of the following functions has an inverse that is also a function?

• f(x) = 2x² - 3x + 5
• f(x) = 2x³ + 4x² - 6x + 1
• f(x) = 4x³ - 3
• f(x) = x⁶

What is the inverse of
f(x) = (3/4)x - 15?

• f^-1(x) = (3/4)x + 45/4
• f^-1(x) = (4/3)x + 20
• f^-1(x) = (4/3)x + 15
• f^-1(x) = (3/4)x + 20

What is the inverse of
f(x) = 6x - 42?

• f^-1(x) = 6x + 7
• f^-1(x) = x/6 + 42
• f^-1(x) = x/6 + 7
• f^-1(x) = x/6 - 7

You invest $700 in a savings account at 1.7% interest compounded monthly. Which equation represents how much money you will have after t years?

• A = 700(1.017/12)^12t
• A = 700(1 + 0.017/12)^t
• A = 700(1 + 0.017/12)^12t
• A = 700(1 + 0.017)^12t

A star has a mass of 1.8 solar masses. It grows continuously at a rate of 5.4% per century. Which equation represents the size of the star after t centuries?

• A = 1.8(1.054)^t
• A = 1.8(1 + 0.054/100)^100t
• A = 1.8e^0.054t
• A = 1.8e^1.54t

The enrollment at a university is 11,500. The enrollment declines at a rate of 4.4% annually. Which equation shows the university's enrollment after t years?

• A = 11,500(1.044)^t
• A = 11,500(1 + 0.044/12)^12t
• A = 11,500(0.956)^t
• A = 11,500e^0.044t

Rewrite 8³=512 as a logarithm.

• log₃512=8

• log₈512=3

• log₅₁₂8=3

• log₈3=512

The equation P(t)=26500(0.955)^t shows the change in population of a city. By what percent is it increasing or decreasing?

• 95.5% increase

• 95.5% decrease

• 4.5% increase

• 4.5% decrease

The equation P(t)=560(1.042)^t shows the change in population of rabbits in a park. By what percent is it increasing or decreasing?

• 104.2% increase

• 204.2% increase

• 4.2% increase

• 4.2% decrease

Which of the following show exponential growth, or increase? (SELECT ALL THAT APPLY)

• y=6(1.07)^x

• y=200(0.83)^x

• y=18(3)^x

• y=12(1.4)^x