What is a function in algebra?
It’s like a machine. You put in one number, and it transforms it into another number using a preset rule. Every time you put in a number you put in before, the function will always give you the same output. The important thing is that it’s always one output for every input. 2 inputs can give the same output, but 1 input can’t have 2 different outputs. Example: y = 2x is a function where you put a number x into the machine, and it outputs a number y which is twice as big as x. (2x) describes what the function does with the variable, and (y) is the output. That’s how I was taught it way back in the day, and it works pretty well for describing functions.
