Bounds for sine and cosine via eigenvalue estimation

Abstract

Define n × n tridiagonal matrices T and S as follows: All entries of the main diagonal of T are zero and those of the first super- and subdiagonal are one. The entries of the main diagonal of S are two except the (n, n) entry one, and those of the first super- and subdiagonal are minus one. Then, denoting by λ(·) the largest eigenvalue,

Keywords

• eigenvalue bounds
• trigonometric inequalities