What are the special angles in trigonometric functions?

(1) special angle trigonometric function value sin0 = 0sin30 = 0.5sin45 = 0.7071radical 2 sin60=0.8660 radical 3 sin 90 = 1cos 0 = 1 Cos30 = 0.866025404 ii.0.707106781root number 2cos60 = 0.5cos90 = 0tan0 = 0tan30 = 0.577350269 root number 3tan45 =1tan60 =/kloc. 0= 1.732050808 root 3cot45 =1cot60 = 0.577350269 root 3cot90 = 0 (2) 0 ~ 90. Look up the trigonometric function table (See below) (3) Changes of trigonometric functions of acute angles (i) All trigonometric functions of acute angles are positive values (ii) When the angle changes from 0 to 90, the sine value increases (or decreases), the cosine value decreases (or increases), and the tangent value increases (or decreases). When changing between 90 degrees, tan α >: 0, cot α >: 0. "Acute trigonometric function" belongs to trigonometry and is an important content in the field of "space and graphics" of mathematics curriculum standard. According to the mathematics curriculum standard, middle school mathematics divides trigonometry into two parts, the first part is in the third stage of compulsory education, and the second part is in the high school stage. The third stage of compulsory education mainly studies the content of acute triangle function and the solution of right triangle. This textbook has a chapter called "Acute Trigonometric Function". Trigonometry in senior high school is the main part of trigonometry, including solving oblique triangles, trigonometric functions, inverse trigonometric functions and simple trigonometric equations. The former part is the important foundation of the latter part, both in content and way of thinking. Mastering the concept of acute trigonometric function and the method of solving right triangle is an important preparation for learning trigonometric function and solving oblique triangle. Attachment: trigonometric function value table sin0=0,

sin 15=(√6-√2)/4，

sin30= 1/2，

sin45=√2/2，

sin60=√3/2，

sin75=(√6+√2)/2，

sin90= 1，

sin 105 =√2/2 *(√3/2+ 1/2)

sin 120=√3/2

sin 135=√2/2

sin 150= 1/2

sin 165=(√6-√2)/4

sin 180=0