求lim 1+1/2+...+1/2^(n-1)/1+1/2^2+...1/2^2(n-1) n→∞

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) 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（已知lim[（2n-1）an]=2,求lim n*an） 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{1+[1/(2n-1)]}^n 求极限：lim(1+1/x)(2-1/x²) 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(1-2x)^(1/x), lim arctan[1/(x^2-1)] 求左右极限 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,