第10章 10.2

(1)

$\log_5 5 = 1$

(2)

$\log_4 16 = \log_4 4^2 = 2$

(3)

$\log_{16} 4 = \log_{16} 16^{\frac{1}{2}} = \frac{1}{2}$

(4)

$\log_{10} 0.1 = \log_{10} 10^{-1} = -1$

(5)

$\log_4 1 = \log_4 4^0 = 0$

(6)

$\log_7 \frac{1}{49} = \log_7 7^{-2} = -2$

(7)

$\log_9 27 = \log_9 3 \cdot 9 = \log_9 9^{\frac{1}{2}} + \log_9 9 = \frac{1}{2} + 1 = \frac{3}{2}$

(8)

$\log_{\frac{1}{32}} \frac{1}{8} = \log_{\frac{1}{32}} \frac{1}{32^{\frac{3}{5}}} = \frac{3}{5}$

(9)

$\log_2 0.25 = \log_2 \frac{1}{2^2} = -2$

(10)

$\log_2 8^{-1} = \log_2 2^{-3} = -3$