Bab 5 Indeks dan Logaritma

Posted on May 13, 2016 by user

5.2b Penukaran Asas Logaritma

$\begin{array}{l} \log_{a} b = \frac{\log_{c} b}{\log_{c} a} \\ dan \\ \log_{a} b = \frac{1}{\log_{b} a} \end{array}$

Contoh 1:

Cari nilai-nilai yang berikut:

(a) log₂₅ 100

(b) log₃ 0.45

Penyelesaian:

$\begin{array}{l} (a) \log_{25} 100 \\ = \frac{\log_{10} 100}{\log_{10} 25} = \frac{10}{1.3979} = 7.154 \\ (b) \log_{3} 0.45 \\ = \frac{\log_{10} 0.45}{\log_{10} 3} = \frac{- 0.3468}{0.4771} = - 0.727 \end{array}$

Contoh 2:

Cari nilai-nilai yang berikut:
(a) log₄ 8
(b) log₁₂₅ 5
(c) log₈₁ 27
(d) log₁₆ 64

Penyelesaian: