Question

Graph the relation {(5, 0), (0, 5), (5, 1), (1, 5)}. Is it a function? Why or why not?

Answer 1

if x's are repeating then relation isn't a function
if there are same x values more than one then it's not a function

Answer 2

this is how ur graph would look like you can do vertical line test
if line touch two point at the same time then relation is not a function