(1-2的2次方分之1)乘以(1-3的2次方分之1)乘以.乘以(1-10的二次方次方分之1)=(1-1/2)(1+1/2)(1-1/3)(1+1/3)(1-1/4)(1+1/4)×.×(1+1/9)(1-1/10)(1+1/10)=1/2*3/2*2/3*4/3*3/4*5/4*.10/9*9/10*11/10=1/2*11/10=11/20...