Answer
The statement is true.
Work Step by Step
Applying the rules $\qquad a^{-n}=\displaystyle \frac{1}{a^{n}},\ (\displaystyle \frac{a}{b})^{n}=\frac{a^{n}}{b^{n}}$
it follows that $3^{-x}=(\displaystyle \frac{1}{3})^{x}$, so $ f(x)=g(x).$
The statement is true.
