设y=(sinx/x)^(1/x^2)lny=[ln(sinx/x)]/x^2=(lnsinx-lnx)/x^2lim(x→0)lny=lim(lnsinx-lnx)/x^2=lim(1/tanx-1/x)/2x(洛必达法则)=lim(x-tanx)/(2x^2tanx)=lim(x-tanx)/2x^3(等价无穷小)=lim(1-(secx)^2)/6x^2(洛必达法则)=lim-(tanx)^2/6x^2=-1/6所以limy=e^(-1/6)