(ⅰ) $\boldsymbol{\sin(\alpha+\beta)=\sin\alpha\cos\beta+\cos\alpha\sin\beta}$ (ⅱ) $\boldsymbol{\sin(\alpha-\beta)=\sin\alpha\cos\beta-\cos\alpha\sin\beta}$ (ⅲ) $\boldsymbol{\cos(\alpha+\beta)=\cos\alpha\cos\beta-\sin\alpha\sin\beta}$ (ⅳ) $\boldsymbol{\cos(\alpha-\beta)=\cos\alpha\cos\beta+\sin\alpha\sin\beta}$