;
;
) lim _(xarrow +infty )(sqrt ({x)^2+x}-sqrt ({x)^2-x});
) lim _(xarrow +infty )(sqrt ({x)^2+x}-sqrt ({x)^2-x});
(7) lim _(xarrow +infty )(sqrt ({x)^2+x}-sqrt ({x)^2-x}) ;
求lim _(xarrow +infty )(sqrt ({x)^2+x}-x)求
lim _(xarrow +infty )x(sqrt ({x)^2+1}-x)；；
已知lim _(xarrow +infty )(x)^a[ sqrt ({x)^2+1}+sqrt ({x)^2-1}-2x] =bneq 0 x]=b≠0，则
求lim _(xarrow +infty )x(sqrt ({x)^2+1}-x)求
lim _(xarrow 0)dfrac (sqrt {1+5x)-sqrt (1-3x)}({x)^2+2x}= . __
lim _(xarrow infty )(x)^2(sqrt (dfrac {1+{x)^2}({x)^2}}-1)= __
(9)lim _(xarrow 0)dfrac (sqrt {1+5x)-sqrt (1-3x)}({x)^2+2x} .