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