Unit 6 Test Review

A part of exponential function f is graphed on the grid. The inequality best represents the domain as ​ (a)   and the range as ​ (b)   .

Twenty years ago, a collector purchased a painting valued at $850.00. The value of the painting since that time can be modeled by the function f(t)=850(0.78)^t, where t represents the number of years since the initial purchase. Which of the following statements is true?

• The value of the painting has decreased by $187.00 each year.

• The value of the painting has increased by $663.00 each year.

• The value of the painting has increased by 78% each year.

• The value of the painting has decreased by 22% each year.

The table contains some points on the graph of an exponential function.

What is the equation that best represents the table?

Mathematical Equivalence

ON

Thirty years ago, a collector purchased a vintage doll valued at $170.00. The value of the doll since that time can be modeled by the function v(t)=170(1.4)^t, where t represents the number of years since the initial purchase. Which of the following statements is true?

• The value of the doll has increased by 40% each year.

• The value of the doll has decreased by 40% each year.

• The value of the doll has increased by $238.00 each year.

• The value of the doll has decreased by $238.00 each year.

The table contains some points on the graph of an exponential function. What is the equation that best represents the table? Enter your answer in the space provided.

Radioactive material can be described using half-lives. For every half-life that passes, the amount of radioactive material decreases by 50%. If you begin with 30 grams of material, what function can you use to find y, the amount of substance that remains after x half-lives? Write your function in the form y = a(b)^x.

Mathematical Equivalence

ON

The amount of fertilizer in a landscaping company’s warehouse decreases at a rate of 3% per week. The amount of fertilizer in the warehouse was originally 78,000 cubic yards. Which function models the amount of fertilizer in cubic yards left after w weeks?

• There is an asymptote at y = 2

• There is an asymptote at y = 3

• The x-intercept is located at (0, 2)

• The x-intercept is located at (0, 3)

• The y-intercept is located at (0, 3)

Mathematical Equivalence

ON

The starting annual salary for an office worker at a company is $29,000. If the company awards an annual increase of 6.2%, which graph models this situation after the office worker receives x annual increases?

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