f:
**
R
**
**
→
**
**
R
**

This is known as signum function.

Let us check value of f(x) for different values of x

####
**
For x = –1
**

x < 0

So, f(x) = –1

####
**
For x = –2
**

x < 0

So, f(x) = –1

####
**
For
**
**
x =
**
**
1
**

x > 0

So, f(x) = 1

####
**
For x = 2
**

x > 0

So, f(x) = 1

####
**
For x =
**
**
0
**

x = 0

So, f(x) = 0

Now,

Plotting graph

Here,

**
Domain
**
= All values of x = R

**
Range
**
= All values of y

*
Since y will
*
*
have value 0, 1 or –1
*

Range = {0, 1, –1}