This is a simple proof that each real number undergoing a normal operation is equal to a real number.
[tex]\sqrt{-1} = \sqrt{-(1)} = \sqrt{-(\sqrt{1})^{2}}[/tex]
Since,
[tex]\sqrt{x^{y}} = \sqrt{x}^{y}[/tex]
Then,
[tex]\sqrt{-(\sqrt{1})^{2}} = \sqrt{-(\sqrt{1})}^{2}[/tex]
Thus,
[tex]\sqrt{-1} = -\sqrt{1} = -1[/tex]
Or generally,
[tex]\sqrt{-n} = -\sqrt{n}[/tex]

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