原式=lim{[x+(x+x^0.5)^0.5-x]/[(x+(x+x^0.5)^0.5)^0.5+x^0.5]}
=lim{[1+(1/x)^0.5]^0.5/[1+(1+(1/x+(1/x)*(1/x)^0.5)^0.5)^0.5]}
=1/2
(啊 打得眼睛都花了 )
(第二步是上下同时除以(x)^0.5)
原式=lim{[x+(x+x^0.5)^0.5-x]/[(x+(x+x^0.5)^0.5)^0.5+x^0.5]}
=lim{[1+(1/x)^0.5]^0.5/[1+(1+(1/x+(1/x)*(1/x)^0.5)^0.5)^0.5]}
=1/2
(啊 打得眼睛都花了 )
(第二步是上下同时除以(x)^0.5)