The trigonometric function takes the angle (the most commonly used radian system in mathematics, the same below) as the independent variable, and the coordinates of the intersection point between the terminal edge of any angle and the unit circle or its ratio as the dependent variable. Trigonometric functions and numerical tables of trigonometric functions with special angles.

The difference angle formula of trigonometric function of sum and difference angle, also known as trigonometric function subtraction theorem, is the relationship between sum (difference) trigonometric function of several angles and trigonometric function of each angle.

Double angle formula of trigonometric function. The double angle formula of trigonometric function is a trigonometric function that uses its own angle to represent the double angle.

Calculus formula Calculus is a branch of mathematics that studies the differential and integral of functions and related concepts and applications in higher mathematics.

Calculation formula of arch area. The formula of arch area is sector area-triangle area.