K-Functionals and Exact Values of n-Widths of Certain Classes in the Spaces C(2\pi ) and L_1 (2\pi )

For classes of $2\pi $ -periodic functions whose K-functionals are majorized by functions satisfying certain constraints, exact values of Kolmogorov, Bernstein, and trigonometric n-widths in the spaces $C(2\pi )$ and $L_1 (2\pi )$ are obtained. Examples of majorants that satisfy the requirements stated in this paper are given.