1.Simpify the following question
A. 1/cos^2θ-(1+tan^2θ)
B. (sinθ+cosθ)^2-1
C. cosθ/1+sinθ - 1-sinθ/cosθ
Trigonometry 的 simpify 快少少
2009-10-11 10:29 pm
回答 (1)
2009-10-11 10:47 pm
✔ 最佳答案
a. 1/cos2@ - (1 + tan2@)= 1/cos2@ - (cos2@/cos2@ + sin2@/cos2@)
= 1/cos2@ - (cos2@ + sin2@)/cos2@
= 1/cos2@ - 1/cos2@
= 0
b. (sin@ + cos@)2 - 1
= sin2@ + 2sin@cos@ + cos2@ - 1
= (sin2@ + cos2@ - 1) + 2sin@cos@
= (1 - 1) + 2sin@cos@
= 2sin@cos@
c. cos@ / (1 + sin@) - (1 - sin@)/cos@
= [cos2@ - (1 - sin@)(1 + sin@)] / cos@(1 + sin@)
= (cos2@ - 1 + sin2@) / cos@(1 + sin@)
= (1 - 1)/cos@(1 + sin@)
= 0
參考: Physics king
收錄日期: 2021-04-19 15:57:08
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20091011000051KK00967