原式=sin(-4π+1/6π)+cos(13/7π)tan4π-cos(4π+1/3π)
=sin1/6π+cos(13/7π)*0-cos1/3π
=sin1/6π-cos1/3π
=0
注:sin(2kπ+A)=sinA
cos(2kπ+B)=cosB
tan2kπ=0
其中:A,B为任意角
k取整数