1/1+sin θ+1/1+cosθ+1/1+secθ+1/1+cscθ=?
回答 (1)
2016-11-21 1:18 pm
Sol
1/(1+Sinθ)+1/(1+Cosθ)+1/(1+Secθ)+1/(1+Cscθ)
=1/(1+Sinθ)+1/(1+Cscθ)+1/(1+Cosθ)+1/(1+Secθ)
=(1+Cscθ+1+Sinθ)/[(1+Sinθ)(1+Cscθ)]
+(1+Secθ+1+Cosθ)/[(1+Cosθ)+1/(1+Secθ)]
=(2+Cscθ+Sinθ)/(1+Cscθ+Sinθ+1)
+(2+Secθ+Cosθ)/(1+Secθ+Cosθ+1)
=1+1
=2
1/(1+Sinθ)+1/(1+Cosθ)+1/(1+Secθ)+1/(1+Cscθ)
=1/(1+Sinθ)+1/(1+Cscθ)+1/(1+Cosθ)+1/(1+Secθ)
=(1+Cscθ+1+Sinθ)/[(1+Sinθ)(1+Cscθ)]
+(1+Secθ+1+Cosθ)/[(1+Cosθ)+1/(1+Secθ)]
=(2+Cscθ+Sinθ)/(1+Cscθ+Sinθ+1)
+(2+Secθ+Cosθ)/(1+Secθ+Cosθ+1)
=1+1
=2
收錄日期: 2021-04-30 21:54:40
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20161121044418AAVUdlH