相关试题
填空题 $$\cos2\alpha = 2\underline{\quad} - 1$$
填空题 $$\cos(\alpha - \beta) = \underline{\quad}$$
填空题 $$\sin(\alpha + \beta) = \underline{\quad}$$
填空题 $$\cos2\alpha = \cos^2\alpha - \underline{\quad}$$
填空题 $$\tan\alpha = \underline{\quad}$$($$\cos\alpha \neq 0$$)
填空题 $$\sin2\alpha = \underline{\quad}$$
填空题 $$\cos2\alpha = 1 - 2\underline{\quad}$$
填空题 $$\sin^2\alpha + \underline{\quad} = 1$$