Tables are presented which make possible quick approximation of a curve by a series of Chebyshev polynomials: f(x) ≈ a 0 /2 Σ i = 1 na i T i (x); n max = 10 The given curve is replaced by linear pieces between 21 equidistant points in the interval 〈- 1; + 1〉. The nth coefficient is computed as a n = Σ K n,j k j + Σ Q n,j q j where K n,j , Q n,j are constants of the tables and k i , q j are constants of the linear piece y = k j x + q j in the jth interval.