There are 18 functions total for complex numbers. At this point, this chapter gives you some basic explanations. The individual functions will refer to this passage.
In school, you learned that any number squared is positive:
22 = 4
(–2)2 = 4
This also means that it is not possible to take the square root of negative numbers:
In the four basic arithmetic calculations, there is an inversion for every operation: addition ↔ subtraction and multiplication ↔ division. Shouldn’t this be applicable to exponentiation ↔ extracting a root? Mathematicians could not stop thinking about this problem. They regarded the call for “completeness ...