3. 指數定律 > 整數指數定律

3.2. 整數指數定律

整數指數定律 包括下面幾條:

1. \(a^{m} \times a^{n} = a^{m+n}\)
   例1：　\(b^{2} \times b^{3} = b^{2+3} = b^{5}\)
2. \(\dfrac{a^{m}}{a^{n}} = a^{m} \div a^{n} = a^{m – n} \)
   例2: \(\dfrac{x^{6}}{x^{2}} = x^{4} \)
3. \((a^{m})^{n} = a^{m \times n} \)
   例3: \((a^{4})^{3} = a^{12} \)
4. \((ab)^{n} = a^{n}b^{n} \)
   例4: \((r^{2}s)^{3} = r^{2\times3}s^{3} = r^{6}s^{3} \)
5. \(\left ( \dfrac{a}{b}\right )^{n} = \dfrac{a^{n}}{b^{n}} \)
   實依條式同第4條公式係一樣嘅。
6. \(a^{0} = 1\)
   例5:  \( (x^{2} y)^{0} = 1 \)
   唔理括號入面係咩, \((一堆數)^{0}\) 化簡後都係1。
7. \(a^{-n} = \dfrac{1}{a^{n}} \)