sin(25π/3)=sin(8π+π/3)=sinπ/3=√3/2
cos(-25π/6)=cos(-4π-π/6)=cos(-π/6)=cosπ/6=√3/2
tan(-29π/4)=-tan29π/4=-tan(7π+π/4)=-tanπ/4=-1
和=√3-1