Question

If a vertical line drawn through a graph crosses it only once, the relation is a function.

True
False

Answer 1

exactly!! its just a restatement of my previous quote in your question!!

Answer 2

if it passes through more than one point it means the graph will have 2 y values for a particular x value which contradicts our definition for a function!!

Answer 3

actually this is known as a test for checking a graph is a function and is known as "vertical line test"

Answer 4

so true?

Answer 5

you bet!