Substituting 361 in place of x,
$f(361 + \sqrt {361} ) = 361 – \sqrt {361} $
$ \Rightarrow f(361 + 19) = 361 – 19$
$ \Rightarrow f(380) = 342$
Substituting 361 in place of x,
$f(361 + \sqrt {361} ) = 361 – \sqrt {361} $
$ \Rightarrow f(361 + 19) = 361 – 19$
$ \Rightarrow f(380) = 342$