Question

What condition does a function need to meet in order to be invertible?

Answer 1

Answer:

A function must be "one-to-one" in order to be invertable meaning that each y-value is associated with only one x-value. You can easily check to see if a function is invertable by using the "horizontal line test" where you run your finger up and down the graph and if at any point your finger is touching two or more points the graph has failed the test.