必修五数列综合练习:求和:(2-3x5^-1)+(4-3x5^-2)+…+(2n-3x5^-n) 急用!
必修五数列综合练习:求和:(2-3x5^-1)+(4-3x5^-2)+…+(2n-3x5^-n) 急用!
sn=(2-3x5^-1)+(4-3x5^-2)+…+(2n-3x5^-n)要详解答案,急用!
1x5+2x5+3x5+4x5+5x5… 麻烦给我一个公式.
求和(1)(a-1)+(a²-2)+…+(an-n)(2)(2-3X5^-1)+(4-3X5^-2)+…+(2
数列的前N项求和数列:1/(1X3),1/(3X5),1/(5X7),……,1/[(2n-1)(2n+1)]呃,这种类型
求数列1/1x2,1/2x3,1/3x4,1/4x5.的前n项和---
一道简便计算数学题1X2+2X3+3X4+4X5...+n(n+1)一1X2+2X3+3X4+4X5...+2013X2
求证:对于自然数n有17/((3X5*2n+1)+(2*3n+1))
求前n项和1.1/(2X5),1/(5X8),1/(8X11)...2.2^2/(1X3),4^2/(3X5),6^2/
S=(1/1x3)+(1/3x5)+省略号+1/(2n-1)(2n+1)
求数列1/2x5,1/5x8,1/8x11...,1/(3n-1)(3n+2)...的前n项和
对任意自然数N,证明3x5 2n+1 +23n+1能被17整除