aliases:
- n 阶行列式「行列式」是一个方阵对应的数值，通过递归展开或行列交换等操作来计算。行列式的理论起源于解线性方程组，它在数学的许多分支以及其他自然科学方面有着广泛的应用，它可以用来表达很多数学性质，从而可以用来解释并推断许多实际现象。常用的行列式有二阶行列式和三阶行列式
由
得到推论：若行列式有两行（列）元素相同，则行列式的值为零
行列式的计算可以依赖 Laplace 定理 和 Cramer 法则
若在
答：不一定
若二阶行列式
答：不一定
若
答：不可能，有
Every weekday morning at 6am, Aiken listens to the traffic report on the radio before she leaves home and drives to her workplace. If the report says there is a traffic jam, Aiken leaves at 7am, otherwise she leaves at 7.30am. However, the report's prediction may not be accurate: when the report says "Jam", there is a 0.8 probability that there will be an actual jam on the road; whereas when the report says "No jam", the probability of an actual jam is 0.1. On any weekday, the probability that the report will say "Jam" is 0.6.
Aiken's boss rewards everyone with 3 for each day of early or on−time arrival, but penalizes 10 for each day of late arrival. However, if Aiken arrives early, she also has to pay an early parking penalty of $5. There is no parking penalty if she arrives on time or late.
How much money does Aiken expect to gain daily from the reward and penalties?
Write your answer as a simple decimal, eg. -3.20. (Note a negative number means a loss, while a positive number means a gain.)
早到概率为广播堵车且没堵车，0.6 乘 0.2 =0.12
准时，0.48 +0.36
迟到，广播没堵车但堵车，0.4 乘 0.1=0.01
并且给出
如果已知
已知一个棕色眼睛男生
棕色男生先验概率为 1/10，
求解两个都是男生的概率