(6) lim _(xarrow a)dfrac ({x)^m-(a)^m}({x)^n-(a)^n} ,

求下列极限:-|||-lim _(xarrow a)dfrac ({x)^m-(a)^m}({x)^n-(a)^n}(aneq 0)

(2) lim _(xarrow 0)dfrac (sin ({x)^n)}({(sin x))^m} (n,m为正整数),

(2) lim _(xarrow 0)dfrac (sin ({x)^n)}({(sin x))^m} (n,m为正整数);

【题目】-|||-(11) lim sqrt [n]({2)^n+(3)^n+(4)^n}= __-|||-(12)设 lim _(xarrow -1)dfra

设 (x)=lim _(narrow infty )dfrac ({x)^n+2-(x)^-n}({x)^n+(x)^-n} 则函数(x)=lim _(narr

cos dfrac (x)({2)^n})（提示：lim _(xarrow infty )(cos dfrac (x)(2)cos dfrac (x)(4)co

(6) lim _(xarrow infty )dfrac (arctan x)(x)

利用等价无穷小的性质，求下列极限：（1）lim _(xarrow 0)dfrac (tan 3x)(2x)（2）lim _(xarrow 0)dfrac (ta

设(x)=lim _(narrow infty )dfrac ({x)^n+2}(sqrt {{2)^2n+(x)^2n}}，则(x)=lim _(narrow

(6) lim _(narrow infty )dfrac ({5)^n-(3)^n}({5)^n+(2)^n}