Chapter 3 shows how equations that have no real roots give rise to imaginary numbers that square to −1, which, in turn, lead to complex numbers. Definitions and examples are given for adding, subtracting, multiplying and dividing complex numbers. Further sections introduce concepts of the norm, complex conjugate, inverse and square-root of a complex number. Finally, it is shown how a complex number is represented as an ordered pair and as a matrix. The chapter summarises key formulae and contains some useful worked examples.
