Math Homework Help

The function that associates each real number to itself is called the identity function and is usually denoted by I.

So, the function f:R->R defined by f(x)=x for all x in R is called the identity function.

From the knowledge of coordinate geometry, y=x represents a straight line passing through the origin and inclined at angle 45° with the x axis.

Clearly the domain and range of the identity function are both equal to R.

We can observe that it is a bijection.