Answer:
[tex]\large\boxed{\log_4\dfrac{1}{9}\approx-1.585}[/tex]
Step-by-step explanation:
[tex]\text{Use}\\\\a^{-n}=\dfrac{1}{a^n}\\\\\log_ab^n=n\log_ab\\=============================\\\\\text{We have}\ \log_43\approx0.7925.\\\\\log_4\dfrac{1}{9}=\log_4\dfrac{1}{3^2}=\log_43^{-2}=-2\log_43\approx(-2)(0.7925)=-1.585[/tex]
