Direct and inverse theorem

Part 1 of ebook "The essence of mathematics: Through elementary problems" provides readers with contents including: mental skills; direct and inverse procedures; structural arithmetic; pythagoras' theorem; arithmetic; standard written algorithms; commutative, associative and distributive laws; word problems; algebra; the binary numeral system; simultaneous linear equations and symmetry;...

190p tieulangtran 28-09-2023 6 1   Download

In the present work we prove some direct and inverse theorems for approximation by trigonometric polynomials in Musielak–Orlicz spaces. Furthermore, we get a constructive characterization of the Lipschitz classes in these spaces.

20p nutifooddau 21-01-2019 14 2   Download

Main properties of the mixed modulus of continuity in the Lebesgue spaces with Muckenhoupt weights are investigated. We use the mixed modulus of continuity to obtain Potapov type direct and inverse estimates of angular trigonometric approximation of functions in these spaces.

24p danhdanh27 07-01-2019 29 1   Download