1) secθ - cosθ = sinθ * tanθ
2) sinθ * cosθ * (tanθ + cotθ) = 1
Verify means the answers should turn out to be X=X
Thanks a lot~
Verify the identity (Trig.)
2008-05-23 10:20 pm
回答 (2)
2008-05-23 10:44 pm
✔ 最佳答案
1. L.H.S.= secθ - cosθ
= 1/cosθ -cosθ
= 1-(cosθ)^2/cosθ
= (sinθ)^2/cosθ
= sinθ * tanθ
= R.H.S
2. L.H.S.
= sinθ * cosθ * (tanθ + cotθ)
= sinθ * cosθ * (sinθ/cosθ + cosθ/sinθ)
= sinθ * cosθ * [(sinθ)^2 + (cosθ * )^2]/ (cosθ*sinθ)
= 1
= R.H.S.
2008-05-24 2:05 am
1.
RHS=sinx*tanx
=sin²x/cosx
=(1-cos²x)/cosx
=1/cosx-cosx
=secx-cosx
=LHS
2.
LHS=sinx*cosx*(tanx+cotx)
=sin²x+cos²x
=1
=RHS
RHS=sinx*tanx
=sin²x/cosx
=(1-cos²x)/cosx
=1/cosx-cosx
=secx-cosx
=LHS
2.
LHS=sinx*cosx*(tanx+cotx)
=sin²x+cos²x
=1
=RHS
收錄日期: 2021-04-15 15:19:08
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080523000051KK00978