you buy the newest 3D television for $1,720. the value of the television decreases by $215 per year.

Question

a. write a function f(y) that shows the value of the tv after a number of years (y). 

 

b. what is the practical domain for your equation?

 

c. what is the practical range for your equation?

 

d. how many years will it be until the tv is worth half of its original value?

Answer 1

a. f(y) = 1720 - 215y

 

b. [0,8] ; the price of the TV will reach $0 after 8 years and the value will not be negative, so the domain can only go from 0 to 8

 

c. [0,1720] ; the range in the price of the TV goes from 1720 originally to 0 after 8 years, so the range can only go from 0 to 1720

 

d. f(y) = 1720 - 215y

    860 = 1720 - 215y

    215y = 860

    y = 4

 

The TV will be worth half of its original value after 4 years.