For the$$ function,

$$f$($x$)$equals$=$StartRoot $9$ minus x EndRoot$9$x$,$

find the following.

$($a$)$

$$ f$(5)$

$($b$)$

$$f$(5)$

$($c$)$

$$f$(3\mathrm{.}3)$

$($d$)$

$$f$(6\mathrm{.}8)$