A, the degree of evil formula
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
Extended data:
Common trigonometric functions are sine function, cosine function and tangent function. Other trigonometric functions, such as cotangent function, secant function, cotangent function, dyadic function, cofactor function, semidyadic function and semifactorial function, are also used in other disciplines, such as navigation, surveying and engineering.
The early study of trigonometric functions can be traced back to ancient times. The founder of trigonometry in ancient Greece was Hippocius in the 2nd century BC. According to the practice of ancient Babylonians, he divided the circumference into 360 equal parts (that is, the radian of the circumference is 360 degrees, which is different from the modern arc system). For a given radian, he gives the corresponding chord length, which is equivalent to the modern sine function.