Question

Is It a Function?

Answer 1

For something to be a function there can only be one x value for every y value (meaning x can’t repeat). To see if the graphs are functions you need to perform the vertical line test. This is where you scan an imaginary line across the graph and if the line passes through two points at the same time, that graph is not a function. This would mean that for the graphs, only graph B is a function. For the mapping part, if an x value has more than two lines attached to it, it’s not a function. This means that mapping A is a function because it only had one line for every x value whereas mapping B had x value 5 with two lines instead of one. For the table, it’s a function if the x value isn’t repeated. This means that table B is a function because no x value repeats whereas in table A the x value 2 repeats twice. That leaves graph A, mapping B, and table A as ‘not a function’. Hope this helped.