You're missing the point. Math (especially advanced) is about precision and rigor. Writing sqrt of something negative is ambiguous. There are better ways of writing it as explained here https://lemmy.world/comment/18924227
m8052
joined 2 years ago
Square root definition does not allow a negative number as an input. Only positives and zero. Although it is possible to expand the definition to negative numbers, complex numbers, matrices.... So unless you followed a course where you thoroughly defined your expansion of sqrt, it only applies to real, positives number and zero. Its the thing with math, you have to define what you work with.
Sqrt(-1) is still wrong tho. I'm commuting a sin by writting it. Correct expression is i^2=-1
You mean limit of sqrt(x) when x->+inf = +inf