| English | Russian |
| the Chebyshev polynomials are orthogonal in the interval -1; 1 over a weight w x . it is easy to establish that these eigenfunctions are orthogonal with the weight p | ортогональны с весом (x, y) |
| the a series expansion in Chebyshev polynomials | разложение в ряд (in orthogonal functions, in rational functions) |