tana = sinb - cosb/sinb + cosb, then sinb + cosb?
回答 (2)
2016-07-04 11:12 am
tana = (sinb - cosb) / (sinb + cosb)
tan²a = (1 - 2sinb cosb) / (1 + 2sinb cosb)
1 + tan²a = 2 / (1 + 2sinb cosb)
1 + tan²a = 2 / (sinb + cosb)²
(sinb + cosb)² = 2 / (1 + tan²a)
sinb + cosb = ±√2 / √(1 + tan²a)
sinb + cosb = ±√2 cosa
tan²a = (1 - 2sinb cosb) / (1 + 2sinb cosb)
1 + tan²a = 2 / (1 + 2sinb cosb)
1 + tan²a = 2 / (sinb + cosb)²
(sinb + cosb)² = 2 / (1 + tan²a)
sinb + cosb = ±√2 / √(1 + tan²a)
sinb + cosb = ±√2 cosa
2016-07-04 12:30 pm
tana mongeau
收錄日期: 2021-04-24 23:29:17
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20160704012655AA3SolY