1, the calculation method of sine function (sin).

If the radian value of the angle is known, the y value of the sine function can be calculated directly in the form of sin x = y. If the degree value of an angle is known, it is necessary to first convert the degree value into radian value, and then calculate the value y of sine function in the form of sin x = y.

2. Calculation method of cosine function (cos).

If the radian value of the angle is known, the value y of the cosine function can be directly calculated in the form of COS x = Y. If the degree value of the angle is known, it is necessary to convert the degree value into the radian value first, and then calculate the value y of the cosine function in the form of COS x = Y..

3. Calculation method of tangent function (tan).

If the radian value of the angle is known, the value y of the tangent function can be directly calculated in the form of tan x = y. If the degree value of an angle is known, it is necessary to first convert the degree value into radian value, and then calculate the value y of the tangent function in the form of tan x = y.

Brief introduction of trigonometric function and matters needing attention in calculation;

1, introduction to trigonometric functions.

Trigonometric function is one of the basic elementary functions, which takes the angle 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. It can also be equivalently defined as the lengths of various line segments related to the unit circle.

Trigonometric function plays an important role in studying the properties of geometric shapes such as triangles and circles, and is also a basic mathematical tool for studying periodic phenomena. In mathematical analysis, trigonometric function is also defined as the solution of infinite series or specific differential equation, which allows its value to be extended to any real value or even complex value.

2. Matters needing attention in trigonometric function calculation.

When calculating sine, cosine and tangent functions, the angle value needs to be converted into radian value by the angle-to-radian formula, that is, x=θ*π/ 180. At the same time, when using the algorithm to calculate trigonometric function, we should also pay attention to the periodicity of trigonometric function, that is, the values of trigonometric function appear repeatedly in a certain range.