gaokao 2021 Q14

gaokao · China · national-A-science Vectors Introduction & 2D Perpendicularity or Parallel Condition

14. Given vectors $\vec{a} = (3,1)$, $\vec{b} = (1,0)$, $\vec{c} = \vec{a} + k\vec{b}$. If $\vec{a} \perp \vec{c}$, then $k = \_\_\_\_$.

14. Given vectors $\vec{a} = (3,1)$, $\vec{b} = (1,0)$, $\vec{c} = \vec{a} + k\vec{b}$. If $\vec{a} \perp \vec{c}$, then $k = \_\_\_\_$.