化简:(1)sin(\alpha +\beta )cos(\gamma -\beta )-cos(\beta +\alpha )sin(\beta -\gamma )=_
解析: \$\sin ( \alpha + \beta ) \cos ( \gamma - \beta ) - \cos ( \beta + \alpha ) \sin ( \beta - \gamma )\$ \$= \sin ( \alpha + \beta ) \cos ( \beta - \gamma ) - \cos ( \alpha + \beta ) \sin ( \beta - \gamma )\$ \$= \sin [ ( \alph...
If "cos"^(-1)alpha+"cos"^(-1)beta+"cos"^(-1)gamma=3pi, then find alpha(beta+gamma)+beta(gamma+alpha)+gamma(alpha+beta).
解析: \$\sin ( \alpha + \beta ) \cos ( \gamma - \beta ) - \cos ( \beta + \alpha ) \sin ( \beta - \gamma )\$ \$= \sin ( \alpha + \beta ) \cos ( \beta - \gamma ) - \cos ( \alpha + \beta ) \sin ( \beta - \gamma )\$ \$= \sin [ ( \alpha...