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