習題庫 向量a=(1,-2),b=(6,3),則a與b的夾角為A.60°B.90° C.120° D.150... 來源:國語幫 5.55K 問題詳情:向量a = (1,-2),b = (6,3),則a與b的夾角為A.60° B.90° C.120° D.150°【回答】B知識點:平面向量題型:選擇題 A1 B6