Which of the following defines a function on a given domain?

Question

Which of the following defines a function on a given domain?

a. f(x) = x/x+3' domain = {1,2, - 3, - 6}

b. f(x)= sqrt{x-3}; domain= {3,4,0}

c. f(x)- x/1-³√x ; domain = {1,2,3}

d. f(x)= sqrt{x-5} ; domain= {5,6,7}

I have answered D but I am not sure.

Answer 1

1. A cannot be the anwer -3 is not in the domain.
2. B cannot be be the answer. Domain is anything greater than or equal to 3.

C and D are correct. Did you have a typo by any chance?