就是特殊的0°至360°
ä¸è§å½æ°æ¯æ°å¦ä¸å¸¸è§çä¸ç±»å ³äºè§åº¦çå½æ°ãä¹å¯ä»¥è¯´ä»¥è§åº¦ä¸ºèªåéï¼è§åº¦å¯¹åºä»»æ两边çæ¯å¼ä¸ºå åéçå½æ°å«ä¸è§å½æ°ï¼ä¸è§å½æ°å°ç´è§ä¸è§å½¢çå è§åå®ç两个边é¿åº¦çæ¯å¼ç¸å ³èï¼ä¹å¯ä»¥çä»·å°ç¨ä¸åä½åæå ³çåç§çº¿æ®µçé¿åº¦æ¥å®ä¹ãä¸è§å½æ°å¨ç 究ä¸è§å½¢ååçå ä½å½¢ç¶çæ§è´¨æ¶æéè¦ä½ç¨ï¼ä¹æ¯ç 究å¨ææ§ç°è±¡çåºç¡æ°å¦å·¥å ·ãå¨æ°å¦åæä¸ï¼ä¸è§å½æ°ä¹è¢«å®ä¹ä¸ºæ 穷级éæç¹å®å¾®åæ¹ç¨ç解ï¼å 许å®ä»¬çåå¼æ©å±å°ä»»æå®æ°å¼ï¼çè³æ¯å¤æ°å¼ã
ä¸äºç¹æ®è§çä¸è§å½æ°å¼å 为ç»å¸¸ç¨å°ï¼æ以è¦ç¢è®°ï¼å¯¹æé«ä½é¢é度å¾æ帮å©ã
sin30 0.5
sin45 0.7071 二分之根号2
sin60 0.8660 二分之根号3
sin90 1
cos0 1
cos30 0.866025404 二分之根号3
cos45 0.707106781 二分之根号2
cos60 0.5
cos90 0
tan0 0
tan30 0.577350269 三分之根号3
tan45 1
tan60 1.732050808 根号3
tan90 无
cot0 无
cot30 1.732050808 根号3
cot45 1
cot60 0.577350269 三分之根号3
cot90 0
|360°| 270°| 0° | 15° | 30° | 37° | 45°
sin | 0 | -1 | 0 |(√6-√2)/4 | 1/2 | 3/5 |√2/2
cos | 1 | 0 | 1 |(√6+√2)/4 |√3/2 | 4/5 |√2/2
tan | 0 | 无值| 0 | 2-√3 |√3/3 | 3/4 | 1
______________________________________________________________________
______________________________________________________________________
sin15° = [sqrt(6)-sqrt(2)]/4; cos15° = [sqrt(6)+sqrt(2)]/4;
tan15° = 2-sqrt(3);
sin18° = [sqrt(5)-1]/4; cos18° = sqrt[10+2*sqrt(5)]/4;
tan18° = {3*sqrt[50+10*sqrt(5)]-5*sqrt[10+2*sqrt(5)]}/20;
sin30° = 1/2; cos30° = sqrt(3)/2;
tan30° = sqrt(3)/3;
sin36° = sqrt[10-2*sqrt(5)]/4; cos36° = [sqrt(5)+1]/4;
tan36° = {sqrt[50-10*sqrt(5)]-sqrt[10-2*sqrt(5)]}/4;
sin45° = sqrt(2)/2; cos45° = sqrt(2)/2;
tan45° = 1;
sin54° = [sqrt(5)+1]/4; cos54° = sqrt[10-2*sqrt(5)]/4;
tan54° = {3*sqrt[50-10*sqrt(5)]+5*sqrt[10-2*sqrt(5)]}/20;
sin60° = sqrt(3)/2; cos60° = 1/2;
tan60° = sqrt(3);
sin72° = sqrt[10+2*sqrt(5)]/4; cos72° = [sqrt(5)-1]/4;
tan72° = {sqrt[50+10*sqrt(5)]+sqrt[10+2*sqrt(5)]}/4;
sin75° = [sqrt(6)+sqrt(2)]/4; cos75° = [sqrt(6)-sqrt(2)]/4;
tan75° = 2+sqrt(3);
sin90° = 1; cos90° = 0;
tan90° = ∞;