Answer:
(C) [tex]f(x)={\frac{1}{81}}[/tex]
Step-by-step explanation:
The given expression is:
[tex]f(x)=9^-2[/tex]
Upon solving the above expression, which can be written as:
[tex]f(x)=({\frac{1}{9}})^2[/tex]
[tex]f(x)={\frac{1}{81}}[/tex]
which is same as the expression given in the option (C) that is [tex]f(x)={\frac{1}{81}}[/tex], hence the option C is correct.
