Abstract
This chapter introduces the definition of nonlinear transformations, their basic properties, and components. It explains their main applications through different examples and gives a first classification, their restrictions, and extensions. It includes special cases showing that it is possible to transform nonlinear equations into linear equations, using nonlinear transformations and it also describes the Least Squares method.
Keywords: Double homothetic factor, Least squares method, Linear transformation, Linearization, Logarithmic model, Nonlinear transformation, Reciprocal model.