sn=(2-3x5^-1)+(4-3x5^-2)+…+(2n-3x5^-n)要详解答案,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.
必修五数列综合练习:求和:(2-3x5^-1)+(4-3x5^-2)+…+(2n-3x5^-n) 急用!
求和(1)(a-1)+(a²-2)+…+(an-n)(2)(2-3X5^-1)+(4-3X5^-2)+…+(2
S=(1/1x3)+(1/3x5)+省略号+1/(2n-1)(2n+1)
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/
用数学归纳法证明1/(1x3)+1/(3x5)+1/(5x7)…1/(2n-1)(2n+1)=n/(2n+1)
解方程组X2+X3+X4=1 X1+X2+X3=5 X3+X4+X5=-5 X4+X5+X1=-3 X5+X1+X2=2
对任意自然数N,证明3x5 2n+1 +23n+1能被17整除
求数列1/1x2,1/2x3,1/3x4,1/4x5.的前n项和---