Multivariate Polynomial Approximation

1 Basic Principles and Facts.- 2 Gegenbauer Polynomials.- 3 Multivariate Polynomials.- 4 Polynomials on Sphere and Ball.- 5 Approximation Methods.- 6 Approximation on the Sphere.- 7 Approximation on the Ball.- 8 Tomography.- A Legendre Basis.- B Zeros of the Kernel Function.- C Newman-Shapiro Operators.- D Reconstruction.- E Solutions.