Title: 10_1 Complex Arithmetic
Course: HELM Workbooks 2023-2024 > Section: HELM 10: Complex Numbers

Complex numbers are used in many areas of engineering and science. In this quiz we define what a complex number is and explore how two such numbers may be combined together by adding, subtracting, multiplying and dividing. We also show how to find ‘complex roots’ of polynomial equations.

A complex number is a generalisation of an ordinary real number. In fact, as we shall see, for each complex number there is a pair of real numbers ordered in a particular way. Fundamental to the study of complex numbers is the symbol \(i\), or sometimes \(j\), with the property \(i^2 = −1\). The algebra of complex numbers is similar to the usual algebra of real numbers.