All the zeros x2 i = 1(1)2m of the Chebyshev polynomials T2(x), m = 0(1)n, are found recursively just by taking n2n-1 real square roots. For interpolation or integration of (x), given (x2), only x2 is needed to calculate (a) the (2m - 1)-th degree Lagrange interpolation polynomial, and (b) the definite integral over [-1, 1], either with or without the weight function (1 - x2)-1/2 the former being exact for (x) of degree 2m+1 - 1. © 1969, ACM. All rights reserved.