Question

Which equation represents a function?

Answer 1

All the answers except C has a Vertical Line when graphed. It must pass the Vertical line test in order to be a function.

Vertical Line Test: If you can draw a vertical line anywhere on a graph so that it hits the graph in more  than one spot, then the graph is NOT a function.

C.) can pass the test since it's a horizontal line.

Hope this helps!