Question

F(x)=raiz x+9
a)F(X+9)=
b)F(x^2-9)=
c)F(x^4-9)=
d)F(x^2+6)=

Answer 1

Sólo debes sustituir:
$f(x)= \sqrt{x+9} \\ a)f(x+9)= \sqrt{(x+9)+9}= \sqrt{x+18} \\ b)f(x^2-9)= \sqrt{(x^2-9)+9}= \sqrt{x^2}=|x|$

Saludos!