平行看斜率、垂直看 k1k2=−1;距离公式两套。
Suppose that we have a coin which comes up heads with probability p, and tails with probability q. Now suppose th…
一枚偏币,正面的概率是 p。连扔两次,第一次正面和第二次反面——这两件事到底算不算独立?