2L忌廉蘇打+復習

復習數學中...發現有好多基礎的問題不懂...
先不管了...考完再說...

(1)add the multiple of a row to another row without changing determinant
(2)det(AB)=det(A)*det(B)
(3)in binomial distribution, mean is np and variance is np(1-p)