Question

If $f:N\to N,f\left(x\right)=x+3$, then $f^{-1}\left(x\right)=$_____

• A. $x+3$
• B. does not exist
• C. $x-3$
• D. $3-x$

Answer 1

The correct option is B does not exist

$f\left(x\right)=x+3$
$R_f=N-\{1,2,3\}\ne$ Co-domain $\left(f\right)$
Hence, function is into.
Hence, $f^{-1}\left(x\right)$ does not exist.