6.1 Local Approximation Methods
6.2 Ordinary Regression as Approximation
6.4 Least-Squares Orthogonal Polynomial Approximation
6.7 Approximation through Interpolation and Regression
6.8 Piecewise Polynomial Interpolation
6.11 Shape-Preserving Approximation
6.12 Multidimensional Approximation
6.13 Finite Element Approximations