Describes the development of number systems beginning with natural numbers and how they gradually extend through positive integers, integers and rationals to real numbers. Some history on the development of real numbers from its Greek beginnings. A series of quizzes by California State University, Stanislaus. Linear functions Gives a concise summary about linear functions with links to sample calculations and exercise problems.
Complex numbers Describes the rules of complex arithmetic and the complex conjugate.
The origin of complex numbers Brief history of complex numbers by the University of Toronto. Includes course materials and lesson plans, problems, puzzles and reference materials. Precalculus Topics discussed are algebra, trigonemetry, complex numbers, functions and probability.