In \(a^n\), \(a\) is the base and \(n\) the index. For positive integer \(n\), it represents \(n\) equal factors. Index laws follow by counting, grouping or cancelling these factors.
| Operation | Law |
|---|---|
| Multiply powers with the same base | \(a^ma^n=a^{m+n}\) |
| Divide powers with the same nonzero base | \(\dfrac{a^m}{a^n}=a^{m-n}\) |
| Raise a power to a power | \((a^m)^n=a^{mn}\) |
| Raise a product to a power | \((ab)^n=a^nb^n\) |
| Raise a quotient to a power, \(b\ne0\) | \(\left(\dfrac ab\right)^n=\dfrac{a^n}{b^n}\) |
Example
\(\dfrac{(2x^3)^2x}{4x^2}=\dfrac{4x^7}{4x^2}=x^5\), for \(x\ne0\).
These are multiplication and division rules. \(x^3+x^4\) cannot be simplified to \(x^7\); adding terms does not concatenate their factors.
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