Definition:Square Root/Negative Real
< Definition:Square Root(Redirected from Definition:Square Root of Negative Number)
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Definition
Let $x \in \R_{< 0}$ be a (strictly) negative real number.
Then the square root of $x$ is defined as:
- $\sqrt x = i \paren {\pm \sqrt {-x} }$
where $i$ is the imaginary unit:
- $i^2 = -1$
Hence:
- $\sqrt{-1} = i$
Also see
Sources
- 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): square root
- For a video presentation of the contents of this page, visit the Khan Academy.