Factsheet: Laws of indices

Author

Tom Coleman

Summary
A list of laws of indices.

The associated study guide for this factsheet is Guide: Laws of indices. If you would like to know more about these, please read the guide.

Throughout this factsheet, \(a, b\) are positive real numbers, \(r\) and \(s\) are real numbers, and \(n\) is a positive whole number.

Laws of indices

Law 1: \(\quad a^r·a^s = a^{r+s}\).

Law 2: \(\quad\dfrac{a^r}{a^s} = a^{r-s}\).

Law 3: \(\quad(a^r)^s = a^{r·s}\).

Law 4: If \(a\) is non-zero, then \(a^0 = 1\).

Law 5: \(\quad a^{-r} = \dfrac{1}{a^r}\)

Law 6: \(\quad\displaystyle a^{1/n} = \sqrt[n]{a}.\)

Law 7: \(\quad a^r \cdot b^r = (ab)^r\).

Law 8: \(\quad\dfrac{a^r}{b^r} = \left(\dfrac{a}{b}\right)^r\).

Law 9: \(\displaystyle \quad a^{1/n} \cdot b=\sqrt[n]{a \cdot b^n}\).

Law 10: \(\displaystyle\quad\sqrt[n]{a\cdot b}=\sqrt[n]{a}\cdot\sqrt[n]{b}\).

For more on the subject, please go to Guide: Laws of indices



Version history and licensing

v1.0: created in 05/24 by tdhc.

This work is licensed under CC BY-NC-SA 4.0.

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