-1/罩吵(2kπ+π/2) x趋于1/(2kπ+π/物清侍2) lim sin(1/x)=sin(2kπ+π/2)=1 x趋于-1/(2kπ+π/2) lim sin(1/x)=-sin(2kπ+π/2)=-1 所以正友极限不存在。
