Chebyshev orthogonal polynomial basis.
Mathematical Formulation Chebyshev polynomials of the first kind \(T_n(\xi)\) are orthogonal with respect to the weight function \(w(\xi) = \frac{1}{\sqrt{1-\xi^2}}\) on \([-1, 1]\). The recurrence relation is:
\[
T_0(\xi) = 1, \quad T_1(\xi) = \xi, \quad T_{n+1}(\xi) = 2\xi T_n(\xi) - T_{n-1}(\xi)
\]
Implementation Algorithm
evaluate() computes polynomial values using the 3-term recurrence relation.
getJacobiMatrix() constructs the symmetric tridiagonal Jacobi matrix \(\mathbf{J}\) with \(\alpha_i = 0\) and off-diagonal \(\beta_1 = \frac{1}{\sqrt{2}}\), \(\beta_i = 0.5\) for \(i \ge 2\).