身為一名junior high school student，我深知這個(gè)社會(huì)對(duì)我們有太多不友好：向量、向量叉乘、行列式……難道junior high school student就不能享受公式推導(dǎo)的過程了嗎？難道junior high school student就應(yīng)當(dāng)被降維打只因嗎？于是，鄙人用簡(jiǎn)單的知識(shí)on middle school textbook，easily推出了這個(gè)美麗的公式，希望各位junior high school student能夠站起來反抗壓迫！記住， Never Gonna Give You Up！