5.5 Complex numbers

The complex numbers extend the real numbers by adding the square root of –1. Mathematicians typically call this square root i, but people in fields like electrical engineering use j. Python uses j. I strongly disagree with this choice, but it is part of the language now. As you work with Python and read technical documents, you may need to translate mentally back and forth between i and j.

The cmath module provides many functions and methods for working with complex numbers. These include complex versions of inf, nan, e, pi, tau, and the trigonometric, hyperbolic, exponential, and logarithmic functions.

I cover complex numbers in sections 3.9 and 4.5 of Dancing with Qubits. [DWQ]

5.5.1 Creating complex numbers

For a and b real numbers, a complex number z looks like a + b i. The real part Re(z) of z is a, and the imaginary part ...