(1)sin(4π/3)cos(7π/6)tan(21π/4)=sin(π+π/3)cos(π+π/6)tan(5π+π/4)=-sinπ/3*(-cosπ/6)tanπ/4=-√3/2*(-√3/2)*1=3/4(2)sin(23π/6)cos(-17π/4)tan(π/8)tan(3π/8)=sin(4π-π/6)cos(-4π-π/4)tan(π...