y=(1-cosx)^(1/lnx)lny=(1/lnx)ln(1-cosx)=(x²/2)/lnx =x²/(2lnx)lim【x→0+】lny=lim【x→0+】x²/(2lnx)=lim【x→0+】(2x)/(2/x)=lim【x→0+】x²=0故lim【x→0+】=1