求 (1) lim ((1^2+2^2+3^2+...+n^2)/n^3) (2) lim (1-1/4)(1-1/9)(1-1/16)...(1-1/n^2) 注:n^2为n 的二次方

求极限lim 2/(3^n-1) 求lim(1-cosx)/x^2求lim(1-COSX)/X^2X→0 lim(2an+4bn)=1 lim(3an-bn)=2 求lim(an+bn) lim(2an+4bn)=1 lim(3an-bn)=2 求lim(an+bn) 极限的简单运算lim an=3, lim bn=1/3, 求lim ((an-3bn)/2an) 数列极限（已知lim[（2n-1）an]=2,求lim n*an） lim(1+2x)^1/x求极限（lim下是x~0) 若lim[(2n-1)an]=1 求lim(n*an)的值 数列极限的运算lim an/(an+1) =2 求lim 2anlim (2n+1)*an=3 求lim n*an 求极限 lim sin pi(n^2+1)^(1/2) 求极限 lim sin pi*(n^2+1)^(1/2) 求极限：lim{1+[1/(2n-1)]}^n 求极限：lim(1+1/x)(2-1/x²) 求极限lim(1-2/x+3/x^2)^x lim[(2n-1)an]=2,求limnan lim(1-cost)=t^2/2求解答, 求极限：lim(1-2x)^(1/x), lim arctan[1/(x^2-1)] 求左右极限