Question

Câu 14 làm sao v ạ.

Answer 1

Lý thuyết: \(\left(\overrightarrow{a};\overrightarrow{b}\right)=180^0-\left(-\overrightarrow{a};\overrightarrow{b}\right)\)

Ta có: \(\left(\overrightarrow{CA};\overrightarrow{CB}\right)=\widehat{C}=40^0\Rightarrow\left(\overrightarrow{AC};\overrightarrow{CB}\right)=180^0-40^0=140^0\)