Lösung 3.1:2f
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Version vom 14:19, 22. Okt. 2008
The cube root of a number is the same thing as the number raised to the power 1/3, i.e. \displaystyle \sqrt[3]{a} = a^{1/3}\,\textrm{.} If we therefore write the number 8 as a product of its smallest possible integer factors
| \displaystyle 8 = 2\cdot 4 = 2\cdot 2\cdot 2 = 2^{3} |
we see that
| \displaystyle \sqrt[3]{8} = \sqrt[3]{2^{3}} = \bigl(2^{3}\bigr)^{1/3} = 2^{3\cdot\frac{1}{3}} = 2^{1} = 2\,\textrm{.} |
Note: Taking the cube root can thus be seen as cancelling the operation of raising a number to the power 3, i.e. \displaystyle \sqrt[3]{5^{3}} = 5\,, \displaystyle \ \sqrt[3]{6^{3}} = 6\, etc.
