This chapter gives an introduction to the theory of approximation methods for the solution of operator equations and for the solution of related variational problems. In the first section we formulate the basic approximation problems and their setting.
- 60.D. Braess, Finite Elements, 3rd edn. (Cambridge University Press, Cambridge, 2007). Theory, Fast Solvers, and Applications in Elasticity Theory. Translated from the German by L.L. SchumakerGoogle Scholar
- 65.F. Brezzi, M. Fortin, Mixed and Hybrid Finite Element Methods. Springer Series in Computational Mathematics, vol. 15 (Springer, New York, 1991)Google Scholar