求极限（给出过程）lim(x趋于+∞）x[(√x^2+1) -x]= ()

lim(x趋于+∞）x[(√x^2+1) -x] =lim(x趋于+∞）x[(√x^2+1) -x]*[(√x^2+1) +x] /[(√x^2+1) +x] =lim(x趋于+∞）x/[(√x^2+1) +x] =lim(x趋于+∞）1/[√(1+x^-2) +1] =1/(1+1) =1/2