Answer: Okkkkkkkk so, i know that the circle is NOT a function because it doesnt pass the vertical line test. *To use the vertical line test, take a ruler or other straight edge and draw a line parallel to the y-axis for any chosen value of x. If the vertical line you drew intersects the graph more than once for any value of x then the graph is not the graph of a function.
Looking at the graph we can determain the domain is indeed greater or equal to negative 4 and less than or equal to 4.
x2+y2=16 is correct (4*4=16), and the last one... doesnt really make sense to me. So im guessing thats wrong.
