Question

What is the purpose of functions?

Answer 1

@jim_thompson5910

Answer 2

Functions are practically everywhere in math and in the real world as well. For example, a vending machine has a series of buttons. The buttons are inputs where if you push a "coke" button, then you'll get a coke drink. So the domain here is the set of buttons to press. The range is the set of drinks you can get.

Another example is with temperature conversion. Going from Celsius to Fahrenheit uses a formula which is in effect a function. You plug in the known temperature in Celsius (input x) and out comes the temperature in Fahrenheit (output y)

There are many other examples all of which can be found here

http://www.educationworld.com/a_curr/mathchat/mathchat010.shtml

and other websites as well