一題G.Maths問題和四題A.Maths問題

抹茶可樂

Originally posted by SusanCrystal at 2005-2-20 05:15 AM:
θ+φ=π/4
tan(θ+φ)=1
(tanθ+tanφ)/(1-tanθtanφ)=1
tanθ+tanφ=1-tanθtanφ
tanθ+tanθtanφ+tanφ=1
tanθ+tanφ(tanθ+1)=1
tanφ(tanθ+1)=1-tanθ
tanφ=(1-tanθ)/(1+tanθ)
1+tanφ=(1+tanθ)/(1+tanθ) + (1-tanθ)/(1+tanθ)
1+tanφ=2/(1+tanθ)
(1+tanθ)(1+tanφ)=2

繼
If θ=φ,θ=π/8
(1+tanπ/8)(1+tanπ/8)=2
(1+tanπ/8)^2=2
1+tanπ/8=√2 (rej.-√2)
tanπ/8=√2-1

碧咸

重有邊題未有人做到

[oscar:警告！不要再灌水！]

[ Last edited by oscar on 2005-2-23 at 07:37 PM ]