正弦定理管两角一边,余弦定理管两边一夹角;已知两边一对角要当心多解(sinAa=sinBb)。
Poker players sometimes wonder why a four of a kind beats a full house. A poker hand is a random subset of 5 elements…
一副牌五张,四条比葫芦大。不是因为四条"更强",是因为四条更难得——624 种对 3744 种,整整六倍。