1、sin 30= 1/2。

2.sin 45= root number 2/2.

3.sin 60= root number 3/2.

Second, cos degree formula

1, cos 30= root number 3/2.

2, cos 45= root number 2/2.

3、cos 60= 1/2 .

Three. Sunlight formula

1, tan 30= root number 3/3.

2. Tan 45= 1.

3.tan 60= root number 3.

The main application methods of trigonometric function are:

The trigonometric function takes the angle (the most commonly used radian system in mathematics, the same below) as the independent variable, and the coordinate or its ratio of the terminal edge of the angle corresponding to any angle intersecting with the unit circle as the dependent variable. It can also be equivalently defined as the lengths of various line segments related to the unit circle.

The concepts of sine and cosine in trigonometry were first introduced by Indian mathematicians, who also made sine tables more accurate than Ptolemy.

The chord table made by Ptolemy and Hipparchus is a round full chord table, which corresponds to an arc, and the chord is sandwiched in the middle of the arc. Unlike Indian mathematicians, they correspond the half chord (AC) to the half arc (AD) of the whole chord, that is, AC corresponds to ∠AOC. In this way, they created a sine table instead of a full chord table.