中三3b總復習8
20)4cos^2(90˚-θ)+4sin^2(90˚-θ)+4
22)cos(90˚-θ)((tan^2(90˚-θ)+1)
我不會做,help me 要步驟
中三3b總復習8
2009-03-14 10:11 pm
回答 (1)
2009-03-15 1:21 am
✔ 最佳答案
20)4cos2(90˚-θ)+4sin2(90˚-θ)+4=4sin2θ+4cos2θ+4
=4(sin2θ+cos2θ)+4
=4(1)+4
=8
22)cos(90˚-θ)((tan2(90˚-θ)+1)
=sinθ[(1/tan2θ)+1]
=sinθ(1/sin2θ)
=1/sinθ
收錄日期: 2021-04-23 20:38:45
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090314000051KK00835