Complex Numbers

Mathematical ideas have been evolving regarding numbers and their relationships since ancient numerical systems. Historically, mathematical ideas have evolved from concrete to abstract ones. For instance, a set of natural numbers was created so that all physical objects in the world around us directly correspond to some number within this set. Since arithmetic and algebra have developed, it has become clear that numbers beyond the naturals or integers are necessary, so decimal and rational numbers were introduced. Similarly, around the times of Pythagoras, it was found that rational numbers cannot solve all numerical problems that we could construct with the geometry that was known at that time. This happened when irrational numbers—numbers that result from taking the square root of other numbers and that have no representation as ratios—were introduced.

Complex numbers are an extension of real numbers and include some special numbers that can provide...