X is the independent variable, and the domain, and y is the dependent variable, and the range.
Imaginary line or Half of the earth dividing north east west or south.
Https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjascq6vOLM...
You will find the information you need here. :3 Good luck!
(Says I have to cite my sources so here goes: I just copy/pasted your question into Google lol)
Yes that answer above is correct
