Imaginary unit
The actual definition of the imaginary unit is
It is a square with a negative value. We do not understand what this means, but you can make computations with it.
Explanation
Formally you can define i as the square root of –1 , so
whatever that may be. This definition is clearly outdated, but is still used in school-books. You never see
as i has no real value.
Example 1
By coincedence, the result of the calculation
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is correct, but is wrong, as you treat i like a real value, what it is not. Moreover, brackets must be solved from inside to outside.
Additional information
The Swiss mathematician Leonhard Euler used the letter i for the imaginary unit.