sin 2x - sin4x =cos2x -cos4x
sin2x - 2sinx - cosx +1 =0
cos2x -√3cos x +1 =0
解三角方程13 - 15
2011-03-06 7:50 pm
回答 (1)
2011-03-06 8:33 pm
收錄日期: 2021-04-22 00:53:22
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20110306000051KK00397