Prove that
1.2cosxcos3x=(2cos2x-1)(cos2x+1)
2.sin5A-sin3A-2sinA= -16sin^3 Acos^2A
solve
cos2θ+cos4θ=2cosθ
幾條m2數,幫幫手做~
2010-07-18 7:06 am
回答 (1)
2010-07-18 8:03 am
收錄日期: 2021-04-22 00:48:42
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100717000051KK01601