Hence, the domain of a function consists of all the values that can be given to the machine as the input & the range are the values of all the ossible outputs obtained from the machine. This means that the washing machine is not programmed to take in the cell phone as an input or we say, the cellphone does not fall into the domain of the machine.

You will get an output for the clean pants BUT NOT for the cellphone even though they are together. But, what if we leave our cell phone in our pants while giving it to the machine. Lets take a washing machine for example, we give it dirty clothes(the input) & it gives us clean clothes(the output). We give the machine an input & it gives us an output. Now, depending on whatever value of radius (the input) is, there is a corresponding value of the area(the output).Įvery single machine in the world, works on the concept of a function. The area, hence, is also called the ‘dependant variable‘ while the radius being independent is called the ‘independant variable‘. Here, the area depends on the radius & is said to be ‘a function of the radius’. Thats exactly what the concept of a function is. Hence, we have an example where a quantity depends on another. The area of this circle depends on its radius. This is a major pre-requisite before any Calculus course often dealt with in a separate course called Pre-Calculus. Before we study differential calculus, it is important to understand the concept of functions and their graphs.

Differential calculus functions