将加的相乘 再乘以 减的相乘(1+1/2)(1+1/3)(1+1/4)……(1+1/100)×(1-1/2)(1-1/3)(1-1/4)……(1-1/100)=3/2*4/3*5/4……101/100×1/2*2/3*3/4*……*99/100=101/2×1/100=101/200
