Final Exam Review 1

1. Mr. Mahoney has his money invested in a stock portfolio. The value, v (x ), of his portfolio can be modeled with the function v(x)=30,000(0.82)x , where x is the number of years since he made his investment. Which statement describes the rate of change of the value of his portfolio?

• 1. It decreases 82% per year.

• 1. It decreases 18% per year.

• It increases 82% per year.

• 1. It increases 18% per year.

Answer explanation

The number in parenthesis is the growth/decay rate. Because it's less than 1, we subtract it from 1 to get the decay percentage. 1 - .82 = .18, which is 18% decrease.

Tags

CCSS.HSF.LE.B.5

The highest possible grade for a book report is 100. The teacher deducts 10 points for each day the report is late. Which kind of function describes this situation?

• linear

• quadratic

• exponential growth

• exponential decay

Answer explanation

deducts = minus, and adding/subtracting is considered linear.

Which of the three situations given is best modeled by an exponential function? 

I. A bacteria culture triples in size every day. 

II. A plant grows by 1 inch every 5 days.

III. The population of a town declines by 8% every 4 years.

• I only

• II only

• I and II

• I and III

Answer explanation

Doubling/tripling/increasing by x% means exponential.

The function f is shown in the table. Which type of function best models the given data?

• exponential decay function

• exponential growth function

• linear function with positive rate of change

• linear function with negative rate of change

Answer explanation

It's growth because the y values are being multiplied by 4.

Tags

CCSS.HSF-LE.A.1A

• Jack said II & III because they coefficients are decreasing

• Joe said I & II because they both have 4 terms

• Jill said I & III because the exponents are decreasing

• Jay said all three because they are polynomials

Answer explanation

-14 and +3 multiply to -42 and add to -11

• Ariel

• Attina

• Alana

• Andrina

Answer explanation

exponents on variables have to be in decreasing order. Constant term (aka no variable) has to be last.

Answer explanation

take the sq root of each term; one ( - ) and one ( + )

Tags

CCSS.HSA.APR.C.4

Answer explanation

-16 * -2 =+32

-16 + -2 = -18

• 5

• -5

• 5, -5

• no solution

Answer explanation

-5 * -5 * -5 = -125