Question

Wendy is logging the number of video game levels she wins per hour. She has determined the function to be f(x) = 6x + 9, where x represents hours and f(x) represents the number of video game levels won. Which of the following options describes the restrictions to the domain and range correctly?

Domain, nonnegative values; range, values greater than −1.5
Domain, nonnegative values; range, values less than −1.5
Domain, nonnegative values; range, nonnegative values
Domain, nonnegative values; range, values greater than 9

Answer 1

You know the smallest number in the domain is 0 and f(x) is increasing with x.
Plug 0 in for x in 6x + 9 to get the smallest number of the range.

Answer 2

I realize that she can do 0 hours of gaming, which would lead to 9 levels, yet , it told me that was wrong

Answer 3

I had chosen D, and it was marked wrong. :/

Answer 4

I guess they're looking for non-negative values for the range, which doesn't quite make sense if they restricted the domain

Answer 5

-1.5 doesn't makes sense at all given the context b/c she can't play -1.5 games.

Answer 6

Thanks peachpi :)