是当X趋向于0吗,如果是的话
令F(x)=x^2-x ,
G(x)=sinx,
F'(x) =2x-1,F'(0)=-1,
G'(x)=cosx,G'(0)=1,
x趋向0时,
(x^-x)/sinx=(F(x)-F(0))/(G(x)-G(0))=F'(0)/G'(0)=-1