The value, V, of a car that is t years old is given by V=f(t)=15000−3600t. Find the domain and range of f(t).

Question

I can't seem to find out how exactly this gets set up to find the domain and range. 

Answer 1

T cannot be negative, so  t>=0

 

The value of the car cannot be negative either.

 

So 15000 - 3600t >=0 --->  15000 >= 3600t

                                           150 >= 36t

 

                                    150/36 >= t

 

                                     50/12 >= t

 

                                      25/6 >= t

 

So the domain is 0 <= t <= 25/6 = 4 and 1/6

 

The range is [0 , 15000]