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The Principal Square Root

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State

The principal square root of a nonnegative number is the nonnegative number that, multiplied by itself, equals it; the radical symbol √ denotes that root.

Show

√25 = 5. Both 5² and (−5)² equal 25, but the radical points at the nonnegative one.

Watch for

√25 is 5, never ±5.

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