sin(35π/6)=sin(6π-π/6)=-sinπ/6=-1/2
cos(-11π/3)=cos(11π/3}=cos(4π-π/3)=cosπ/3=1/2
所以原式为0
画一个一个角为30度的直角三角形 sinπ/3=sin60度=直角三角形60度所对直角边除以斜边
sin(35π/6)=sin(6π-π/6)=-sinπ/6=-1/2
cos(-11π/3)=cos(11π/3}=cos(4π-π/3)=cosπ/3=1/2
所以原式为0
画一个一个角为30度的直角三角形 sinπ/3=sin60度=直角三角形60度所对直角边除以斜边