BigComplexMath#sqrt fails when x is a negative real number

[Onedy]

https://github.com/eobermuhlner/big-math/blob/b659e2f6f3f79a64d6d587c0876dac5e06870012/ch.obermuhlner.math.big/src/main/java/ch/obermuhlner/math/big/BigComplexMath.java#L282 This fails when x is a negative real number because you are dividing (x+abs(x))/abs(x+abs(x)) which is 0/0.

Maybe these are helpful: https://mathworld.wolfram.com/SquareRoot.html and org.apache.commons.numbers.complex.Complex#sqrt() from org.apache.commons:commons-numbers-complex.