Evaluate (complex solution)
\sqrt{21}i\approx 4.582575695i
Real Part (complex solution)
0
Evaluate
\text{Indeterminate}
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\sqrt{21}i
Factor -21=21\left(-1\right). Rewrite the square root of the product \sqrt{21\left(-1\right)} as the product of square roots \sqrt{21}\sqrt{-1}. By definition, the square root of -1 is i.
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