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As I moved through algebra, I was taught that fractional exponents could be evaluated in one of two ways:

$$ x^\frac{a}{b} = (\sqrt[b]{x})^a = (\sqrt[b]x^a)$$

However, suppose $x=-2$ and $a=6$ and $b=4$:

If we evaluate using the first expression, we get:

$$(\sqrt[6]{-1})^4 = DNE$$

This is because we cannot take the even root of a negative number.

But, if we evaluate using the second expression, we get: $$(\sqrt[6]x^4) = 1$$

Any explanation on what is going on? Thanks!

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