看板
[ Math ]
討論串[中學] 一個三角函數問題
共 5 篇文章
內容預覽:
A + B + C = π. 0 < C < B < A < π/2. => π > A + B, B + C, C + A > π/2. 已知sin(A) > sin(B) > sin(C). sin(A) = sin(π - A) = sin(B + C) > sin(B) = sin(A +
(還有208個字)
內容預覽:
幫補Vulpix板友的作法. sin(2C) - sin(2B) = 2cos(B + C)sin(C - B). = 2cos(A)sin(B - C) > 0. => sin(2B) < sin(2C). sin(2B) - sin(2A) = 2cos(B + A)sin(B - A). =
(還有37個字)