close
此文章來自奇摩知識+如有不便請留言告知
標題:
Express cot 2θ in terms of cot θ
發問:
Hence evaluate csc2 22.5°in surd form
最佳解答:
cot 2θ = 1/tan2θ = (1-tan2 θ)/2tanθ
其他解答:
cot 2θ = 1 / tan2θ = (1 - tan^2 θ) / (2tanθ) = (cot^2 θ - 1) / (2cotθ) cot45 = (cot^2 θ - 1) / (2cotθ) where θ = 22.5° 2cotθ = cot^2 θ - 1 cot^2 θ - 2cotθ - 1 = 0 cotθ = 1 + sqrt(2) csc2 22.5° = 1 + cot2 22.5° = 1 + (1 + sqrt(2))^2 = 4 + 2sqrt(2)6A560DB68EC65D60
文章標籤
全站熱搜
留言列表
