- Thread starter
- #1

- Thread starter Yankel
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- Thread starter
- #1

- Jan 30, 2018

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- Mar 5, 2012

- 8,687

Reasons are:

- The power identity $a^{b\cdot c}=(a^b)^c$ breaks down. Consider:

$$-1 = (-1)^{2/3\cdot 3/2} \ne ((-1)^{2/3})^{3/2} = 1^{3/2} = 1$$ - Calculators evaluate it as $x^{0.33333}$, which is undefined for negative x.

Note that we can only define something like $x^{1/3}$ for negative x if the power is a fraction with an odd number in the denominator, but that is generally not supported by calculators.