【sin330°*tan(-13π/3)】/【cos(-19π/6)*cos690°】

问题描述:

【sin330°*tan(-13π/3)】/【cos(-19π/6)*cos690°】

原式=sin(-30)tan(-π/3)/[cos(5π/6)cos(-30)]
=(-1/2)(-√3)/[(-√3/2)(√3/2)
=2√3/3