Answer
$f(5)=1$
$f(9)=4-\sqrt{21}\approx-0.583$
$f(a+2)=4-\sqrt{3a}$
$f(-x)=4-\sqrt{-3x-6}$
$f(x^{2})=4-\sqrt{3x^{2}-6}$
Work Step by Step
$f(x)=4-\sqrt{3x-6};$ $f(5),$ $f(9),$ $f(a+2),$ $f(-x),$ $f(x^{2})$
Substitute $x$ by each corresponding value and simplify:
$f(5)=4-\sqrt{3(5)-6}=4-\sqrt{15-6}=4-\sqrt{9}=4-3=1$
$f(9)=4-\sqrt{3(9)-6}=4-\sqrt{27-6}=4-\sqrt{21}\approx-0.583$
$f(a+2)=4-\sqrt{3(a+2)-6}=4-\sqrt{3a+6-6}=4-\sqrt{3a}$
$f(-x)=4-\sqrt{3(-x)-6}=4-\sqrt{-3x-6}$
$f(x^{2})=4-\sqrt{3x^{2}-6}$
