（3）已知lim _(xarrow 2)dfrac ({x)^2+ax+b}({x)^2-x-2}=2-|||-__，求a，b.

2.已知 lim _(xarrow 1)dfrac ({x)^2+ax+b}(1-x)=1, 求常数a与b的值...

2.求下列极限:-|||-(1) lim _(xarrow 0)dfrac ({x)^2-1}(3{x)^2-x-2}

5.已知 lim _(xarrow 2)dfrac ({x)^2-ax+b}(2-x)=1 ,试求a与b的值.

81.已知 lim _(xarrow a)dfrac (f(x)-A)(x-a)=k, 求 lim _(xarrow a)dfrac ({e)^f(x)-(e)

设 lim _(xarrow 0)dfrac (ln (1+x)-(ax+b{x)^2)}({x)^2}=2, 则设 lim _(xarrow 0)dfrac

求极限：lim _(xarrow 0)dfrac (1-{x)^2-(e)^-(x^2)}(x{sin )^3(2x)} 求极限：

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

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

(13)设 lim _(xarrow 1)dfrac ({x)^3+ax-2}({x)^2-1}=2 求a的值。

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