解:因为: (1-1/2²)x(1-1/3²)x(1-1/4²)...(1-1/n²)
=[(2^2-1)/2^2]x[(3^2-1)/3^2]x[(4^2-1)/4^]...[(n^2-1)/n^2]
=(1x3/2^2)x(2x4/3^2)x(3x5/4^2)...[(n-1)x(n+1)/n^2]
=[1x(n+1)]/(2n)
=(n+1)/(2n)
所以n=2010代入上式得:
原式=2011/4020
答...
全部分解啊,原式=(1-1/2)(1+1/2)(1-1/3)(1+1/3).....(1-1/2010)(1+1/2010)
=1/2*3/2*2/3*4/3.....*2009/2010*2011/2010=1/2*2011/2010=2011/4020