Let X be a complex Banach spcce, and denote by T a strongly continuous semigroup of linear operators denned on X and C by a cosine function of operators with associated sine function S defined on X.

Trigonometry is a branch of mathematics that studies relationships between the sides and angles of triangles. Trigonometry is found all throughout geometry, as every straight-sided shape may be broken ...

Trigonometric identities are powerful tools for simplifying complex equations in math and science. Three core groups—reciprocal, quotient, and Pythagorean—form the foundation. Effective strategies ...