(8) lim _(xarrow 0)dfrac (1-cos 2x)(xln (1+x)) ;

(15)lim _(xarrow 0)dfrac (1-cos 2x)(xsin x)(15)

(3) lim _(xarrow 0)dfrac (1-cos 2x)(xsin x) ()-|||-__

(4) lim _(xarrow 0)dfrac (1-cos 2x)(xsin x) =

[题目]-|||-计算 lim _(xarrow 0)dfrac (1-cos 2x)(xsin x)

(3) lim _(xarrow 0)dfrac (1-cos 3x)({sin )^2x}

(5) 已知极限 lim _(xarrow 0)dfrac (1-cos 2x)(sqrt {1+a{x)^2}-1}=2 ,则 a= __

(2) lim _(xarrow 0)dfrac ({(1-dfrac {1)(2)(x)^2)}^dfrac (2{3)}-1}(xln (1+x))

[题目] lim _(xarrow 0)(dfrac (1)({sin )^2x}-dfrac ({cos )^2x}({x)^2})= __

[题目]求 lim _(xarrow 0)(dfrac (1)({sin )^2x}-dfrac ({cos )^2x}({x)^2})

[题目]求 lim _(xarrow 0)(dfrac (1)({sin )^2x}-dfrac ({cos )^2x}({x)^2})