A function f has an inverse function if and only if f is one - to - one.

Consider the function as .

The table on the left is a table of values for .

The table of values on the right is made up by interchanging the columns of the given table.

The table on the right represent a function because the different input values are matched with  different output values.

So, f(x) is one - to - one and have an inverse function.

\ x \	\ y \
\ \	\      10 \
\ \	\ 6 \
\ \	\ 4 \
\ 0 \	\ 1 \ \ \
2
3	\ \

\ x \	\ y \
\ 10 \	\     \
\ 6 \	\ \
\ 4 \	\ \
\ 1 \	\ 0 \
	2
	3

Yes, the function f(x) have an inverse function.