Maths problem: how to do, thanks?
回答 (1)
2020-10-14 1:59 pm
✔ 最佳答案
2sin^2(22°)+2sin^2(68°)= 2[sih^2(22°)+sin^2(90°-22°)]
= 2[sin^2(22°)+cos^2(22°)] (∵ sin(90°-x) = cos(x).)
= 2 (∵ sin^2(x) + cos^2(x) = 1)
收錄日期: 2021-04-21 14:08:44
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20201014032500AAskkBu