1. **State the problem:** Evaluate $$\log_{\frac{1}{9}} \left( \sqrt[3]{81} \right)^2$$.
2. **Rewrite the expression inside the logarithm:**
$$\left( \sqrt[3]{81} \right)^2 = \left(81^{\frac{1}{3}}\right)^2 = 81^{\frac{2}{3}}$$.
3. **Express 81 as a power of 3:**
$$81 = 3^4$$
So,
$$81^{\frac{2}{3}} = \left(3^4\right)^{\frac{2}{3}} = 3^{4 \times \frac{2}{3}} = 3^{\frac{8}{3}}$$.
4. **Rewrite the base of the logarithm:**
$$\frac{1}{9} = 9^{-1} = (3^2)^{-1} = 3^{-2}$$.
5. **Use the change of base formula for logarithms:**
$$\log_{3^{-2}} 3^{\frac{8}{3}} = \frac{\log_3 3^{\frac{8}{3}}}{\log_3 3^{-2}}$$.
6. **Simplify the numerator and denominator using the power rule of logarithms:**
$$\log_3 3^{\frac{8}{3}} = \frac{8}{3}$$
$$\log_3 3^{-2} = -2$$
7. **Calculate the value:**
$$\frac{\frac{8}{3}}{-2} = \frac{8}{3} \times \frac{1}{-2} = -\frac{8}{6} = -\frac{4}{3}$$.
**Final answer:** $$-\frac{4}{3}$$ which corresponds to option d.
Logarithm Evaluation C4De17
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