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

(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)

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

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

求极限lim _(xarrow 0)dfrac (ln (1+5xsin x))(1-cos x).求极限.

lim _(xarrow 0)dfrac (1-{e)^(x^2)}(xsin 2x)

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

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

.lim _(xarrow infty )xsin dfrac (1)(2x)= __