a-maths~~~~~
2008-06-07 7:52 pm
回答 (1)
2008-06-07 8:05 pm
✔ 最佳答案
let SCR = θ,so that SR= 2sinθ , CR= 2cosθ
the Area of PQRS=(SR)(QR)=(2sinθ)(4cosθ)=4sin2θ
dA/dθ=8cos2θ
let dA/dθ=0
8cos2θ=0
cos2θ=0
1-2sin^2θ=0
sin^2θ=1/2
θ=45 .
so the max value if the Area = 4sin(2)(45)=4//
收錄日期: 2021-04-23 20:32:36
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080607000051KK00977