Updated _nthComplexRoots based on feedback.
Updated _nthComplexRoots based on feedback.

FSMaxB/mathjs,josdejong/mathjs,FSMaxB/mathjs,FSMaxB/mathjs,josdejong/mathjs,FSMaxB/mathjs,josdejong/mathjs,josdejong/mathjs,FSMaxB/mathjs,josdejong/mathjs