1. cos2x= sin^4x+cos^4x 0<=x<=360
2. 2sin^2x-cos2x+1=0 0<=x<=360
a maths
2008-02-15 11:22 pm
回答 (1)
2008-02-15 11:35 pm
收錄日期: 2021-04-25 17:19:04
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080215000051KK01914