Question

The domain and range is always equal for

• A. Constant function
• B. Identity function
• C. Signum function
• D. None of these

Answer 1

The correct option is B Identity function

For Constant function
For domain $=R$
Range $=\left\{c\right\}$
where $c$ is any contant term.

For identity function
The input is always equal to output
$f\left(x\right)=x$
For domain $=R$
Range $=R$

For Signum function
For domain $=R$
Range $=\{-1,0,1\}$