This week we had our midterm and spent most of the week studying for it. But on Friday, we learned about functions, a kind of relation.

A function is a relation that is special and each input has one output, no more. A function is a kind of a relation but a relation is not a kind of function.

On a graph, if any of the points are on the same x axis, then it is not a function. Each point has to be in a different x coordinate.

ex.

A function is unique, and is often named a single letter (f, g, h, etc.), and followed by x, changing into blank.

ex.

ƒ:x → 7x + 6

ƒ is its name, x is the input, the arrow signifies “changing into”, and the final numbers are the output.