Imaginary Number

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Imaginary Number
A number that when squared gives a negative result.

If you square a Real Number you always get a positive, or zero, result. For example 2×2=4, and (-2)×(-2)=4 as well.

So how can we square a number and get a negative result? Because we "imagine" that we can.

The "unit" imaginary numbers (the same as "1" for Real Numbers) is √(-1) (the square root of minus one), and its symbol is i, or j.