✔ 最佳答案
Consider sets only:Left = A U B = A + B - A ∩ BRight = A ∩ (u-B) + A ∩ B + (u-A) ∩ B=(A ∩ u - A ∩ B) + A ∩ B + (u ∩ B - A ∩ B)=A + B - A ∩ B= Left=> P(A U B) =P(A ∩ B')+P(A ∩ B)+P(A' ∩ B)
Note : u=universal setu ∩ A = A
2014-11-13 07:41:54 補充:
***"A U B = A + B - A ∩ B" 是錯誤的式子!!!!!
Ans: 很多考試題目都有使用這ㄍ公式