鼠猫cos灵魂白玉堂死了昭昭也受了伤手握着白玉堂灵魂的手往夜尽http://blog.163.com/smile_jiam/blog/static/625027692008101112839234/2，cos阿尔法贝塔cos贝塔贝塔sin贝塔cos（α-β）×cosβ-sin（α-β）×sinβ=cos[（α-β）+β]=cosα。依据：cos(A+B)=cosAcosB-sinAsinB3，cos2cos2cos21任意向量M；M=(|M|cosα，|M|cosβ，|M|cosγ)√(|M|2cos