Question

f(x)=9x^2

g(x)= sqrt 12-x/3

(f o g)(-4)

Answer 1

$f(x)=9x^2 \\ g(x)=\frac{\sqrt{12-x}}{3}$ So,first step is to write $(fog)(-4)) =f[g(-4)]$

Now we start from inner paranthesis ,we need to first find value of $g(-4) =\frac{\sqrt{12-(-4)}}{3}\\ =\frac{\sqrt{12+4}}{3}\\ =\frac{\sqrt{16}}{3}\\ =\frac{4}{3}\\ (fog)(-4)) =f[g(-4)] =f(\frac{4}{3}) =9(4/3)^{2} =9*(16/9) =144/9 =16$