sin 2 (t) + cos2 (t) = 1. tan 2 (t) + 1 = sec 2 (t) ... sin(α + β) = sin(α) cos(β) + cos(α) sin(β) ... cos(2x) = cos2 (x) – sin 2 (x) = 1 – 2 sin 2 (x) = 2 cos2 (x) – 1.
確定！ 回上一頁
