We study a new method in reducing the roundo error in computing derivatives using Chebyshev collocation methods. By using a grid mapping derived by Koslo and Tal-Ezer, and the proper choice of the parameter , the roundo error of the k-th derivative can be reduced from O(N2k) to O((N jln j)k), where is the machine precision and N is the number of collocation points. This drastic reduction of rou...

We study a new method in reducing the roundo error in computing derivatives using Chebyshev collocation methods. By using a grid mapping derived by Koslo and Tal-Ezer, and the proper choice of the parameter , the roundo error of the k-th derivative can be reduced from O(N) to O((N jln j)k), where is the machine precision and N is the number of collocation points. This drastic reduction of round...

In this paper, the Chebyshev spectral collocation method(CSCM) for one-dimensional linear hyperbolic telegraph equation is presented. Chebyshev spectral collocation method have become very useful in providing highly accurate solutions to partial differential equations. A straightforward implementation of these methods involves the use of spectral differentiation matrices. Firstly, we transform ...

The fractional inverse M (real γ > 0) of a matrix M is expanded in a series of Gegenbauer polynomials. If the spectrum of M is confined to an ellipse not including the origin, convergence is exponential, with the same rate as for Chebyshev inversion. The approximants can be improved recursively and lead to an iterative solver for Mx = b in Krylov space. In case of γ = 1/2, the expansion is in t...

The IBM Power4 processor uses series approximation to calculate square root. We formally verified the correctness of this algorithm using the ACL2(r) theorem prover. The proof requires the analysis of the approximation error on a Chebyshev series. This is done by proving Taylor’s theorem, and then analyzing the Chebyshev series using Taylor series. Taylor’s theorem is proved by way of non-stand...

The present investigation is concerned with the role of bottom slope in the stability properties of two-dimensional disturbances in sheared two-layer immiscible fluids with stepwise densities. A linear analysis of normal mode instability of the interface in an inclined closed tube is carried out using full Navier-Stokes equation using Chebyshev-tau method. It has been observed that Reynolds num...

In this paper, by the Chebyshev-type inequalities we define three mappings, investigate their main properties, give some refinements for Chebyshev-type inequalities, obtain some applications.

We show that every two-bridge knot K of crossing number N admits a polynomial parametrization x = T3(t), y = Tb(t), z = C(t) where Tk(t) are the Chebyshev polynomials and b + degC = 3N . If C(t) = Tc(t) is a Chebyshev polynomial, we call such a knot a harmonic knot. We give the classification of harmonic knots for a ≤ 3. Most results are derived from continued fractions and their matrix represe...

A fast, simple, and numerically stable transform for converting between Legendre and Chebyshev coefficients of a degree N polynomial in O(N(logN)2/ log logN) operations is derived. The basis of the algorithm is to rewrite a well-known asymptotic formula for Legendre polynomials of large degree as a weighted linear combination of Chebyshev polynomials, which can then be evaluated by using the di...

in this paper we introduce a type of fractional-order polynomials basedon the classical chebyshev polynomials of the second kind (fcss). also we construct the operationalmatrix of fractional derivative of order $ gamma $ in the caputo for fcss and show that this matrix with the tau method are utilized to reduce the solution of some fractional-order differential equations.