(1-1⼀2^2)*(1-1⼀3^2)*(1-1⼀4^2)......(1-1⼀2005^2)^2

2025-02-28 15:50:59
推荐回答(3个)
回答1:

(1-1/2^2)*(1-1/3^2)*(1-1/4^2)......(1-1/2005^2)^2
=(1-1/2)(1+1/2)(1-1/3)(1+1/3)(1-1/4)(1+1/4)...(1-1/2005)(1+1/2005)
=1/2*3/2*2/3*4/3*3/4*5/4*...*2004/2005*2006/2005
=1/2*2006/2005
=1003/2005

回答2:

用裂项分解法

回答3:

原始=1*3/(2*2)*(2*4)/(3*3)*......*(2004*2006)/(2005*2005)
=1/2*2006/2005
=1003/2005