8.已知 lim _(xarrow infty )dfrac ((a-1){x)^2-2x+3}({x)^2+x-5}=0 ,求a的值.

求极限lim _(xarrow infty )dfrac (3{x)^2+2x+5}(2{x)^2+3x-1}。求极限。

已知 lim _(xarrow infty )((dfrac {x+2a)(x-a))}^x=8 ,求 a.

求lim _(xarrow infty )dfrac ({x)^2-3x+2}({x)^2-1}-|||-__求

)求下列极限:-|||-(1) lim _(xarrow 1)dfrac ({x)^2-x+1}({(x-1))^2} =-|||-(3) lim _(xarr

求下列极限（3）lim _(xarrow infty )(dfrac ({x)^3}(2{x)^2-1}-dfrac ({x)^2}(2x+1))求下列极限（3

求lim _(xarrow infty )dfrac ({x)^2-1}(2{x)^2-x-1}-|||-__;求;

3.求下列极限:-|||-(1) lim _(xarrow 2)dfrac ({x)^2-3x-4}({x)^2-4} =-|||-(3) lim _(xarr

3.求下列极限:-|||-(1) lim _(xarrow 2)dfrac ({x)^2-3x-4}({x)^2-4} :-|||-(3) lim _(xarr

3.求下列函数的极限.-|||-(1) lim _(xarrow infty )x((e)^dfrac (1{x)}-1);-|||-(2) lim _(xar

求极限lim _(xarrow infty )((1-dfrac {1)(2x))}^dfrac (3{2)x}求极限