证明:当b>0时,(x->b)limx^(1/2)=b^(1/2)1.|f(x)-A|=|x^(1/2)-b^(1/2)|=|(x-b)/(x^(1/2)+x^(1/2))|=0可用|x-b|

问题描述:

证明:当b>0时,(x->b)limx^(1/2)=b^(1/2)
1.|f(x)-A|=|x^(1/2)-b^(1/2)|=|(x-b)/(x^(1/2)+x^(1/2))|=0可用|x-b|