例如： sin (2pi/3) = root 3/ 2
如果唔用計數機可以點計？
究竟點樣計 sin cos ？ (in surd form)
2009-01-14 7:50 pm
回答 (2)
2009-01-14 8:41 pm
✔ 最佳答案
pi = 180度2*pi/3 = (2/3)*180度 = 120度
sin(120度) = sin(180度-120度) = sin(60度) [用CAST方法]
= √(3)/2 = 0.866 [要清楚sin,cos,tan在30,45,60度時的數值 這些數值在數學教科書內應該有]
2009-01-14 8:43 pm
Detailed explanations are provided inside the below link:
http://i404.photobucket.com/albums/pp124/mr_gary_cheung/P1000058.jpg
http://i404.photobucket.com/albums/pp124/mr_gary_cheung/P1000058.jpg
收錄日期: 2021-05-01 09:43:20
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090114000051KK00411