Advantages of functions.
They enable us hide implementation details of a
program. For instance, we have used floor(x), tan(x), degrees(x) without ever
having the knowledge of how they were implemented.
Use of functions improves the readability of a
program which makes it easy to read and understand.
Using functions also help avoid duplication of
code in programs
Other functions a programmer can use are
standard library functions, user defined functions and built in functions
