Tính biết

B==(1+1/2)x(1+1/3)x(1+1/4)x(1+1/5)x....x(1+1/n)
C=(1-1/2Λ2)x(1-1/3Λ2)x(1-1/4Λ2)x...x(1-1/nΛ2
D=3/4.8/9.15/16....9999/10000
E=(1-1/2).(1-1/3).(1-1/4).(1-1/5)......(1+1/n)
F=(1+1/1.3).(1+1/2.4).(1+1/3.5)....(1+1/99.100)