Answer:
Ok, we can define a function as a relation that maps elements from a set (the domain) into elements from another set (the range), such that each element in the domain can be mapped into only one element of the range.
2) Here you choose the autographed poster, and we know that each one of these costs $10.
So, if the artist sold x posters, then he/she would earn x times $10:
earnings = $10*x
So we can create a function:
f(x)
such that f(x) represents the total earnings of the artist for selling x posters.
And we already know the equation for the earnings, so the function will be:
f(x) = $10*x
3) Now, it asks us if the values:
-2, -1, 0, and 1
be appropiate for the domain of the function.
Remember that x represents the number of posters that the artist sold.
Then, if we take x = -2 or x = -1 (like the first two given values) this would mean that the artist sold a negative number of posters, which has no real sense in the situation given. So we can conclude that these values should not be in the domain of the function.
For the other two cases, 0 and 1, these two can be in the domain, because these represent the case where the artist sold only one poster and the case where the artist did not sell any poster (that are two possible cases)