Test 4 Mat 190 - The University Of North Carolina, 2007 (Page 2 of 2) in pdf

Test 4 Mat 190 - The University Of North Carolina, 2007 Page 2

12. The overall stopping distance in feet it takes for a car that is traveling “x” miles per hour can be

approximated by D(x) = 0.05x

+ x.

a) How many feet does it take for a car to stop that is traveling at a speed of 70 mph?

b) If there are 120 feet between you and the car in front of you, what’s the fastest you should be driving in order

to not hit that person if you have to slam on brakes?

13. A music group makes a CD so that the cost of producing “x” CDs is given by C(x) = 2x + 5000 and the

amount of revenue they make from selling “x” CDs is given by R(x) = 10x. The profit P(x) is determined by

subtracting the costs from the revenue. Assume that the group sells every CD they burn.

a) Find the function that represents P(x).

b) How much profit do they make if they make/sell 1000 CDs?

c) How many CDs would they need to sell to break even?

14. The polynomial function I(t) = -0.1t

+ 2.5t represents the yearly income (or loss) from a real estate

investment, where t is time in years after 1970. During what year does the maximum income occur?

15. The length of a table is 15 inches more than its width. If the area of the table is 1924 in

, what is its length?

16. Graph the following function: f(x) = 2(x – 1)

– 6

17. Find the equation of the parabola having a

vertex of (2, 4) and passing through (3, 1).

Test 4 Mat 190 - The University Of North Carolina, 2007 Page 2