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0 pointsspicyj15y ago0 comments

Any positive number has two square roots, but the (present-day) notational convention is always to take the positive square root.

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sid015y ago

Indeed, and I think the reason it's done is simply to make square-root an easy-to-deal-with single-valued function rather than a multifunction. Remember the quadratic formula: the ± in it is in addition to the square root, not part of it.

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