2) An expression is a function if each x value can only give only one y value. If you graph it, you can draw vertical lines at any place along the graph, and each will touch the graph only once.

3) Polynomial means many terms. There is a lot more to it, though.

4) This is a function. Generally, f(x)=y, so f(2)=5 (read “f of 2 equals 5”) means that when x=2, y=5.

2. The basic definition is: That one variable (usually x) is liked to another variable (usually y) in a predictable way.

3. A polynomial function is any function with more than one variable.

4. The function f of 2 is 5. (When you preform function f on 2, you get 5.)