The non-zero vectors a, b and c are related by a=8 b and c=-7 b.

Question

The non-zero vectors $\vec a,\vec b$ and $\vec c$ are related by $\vec a=8\vec b$ and $\vec c=-7\vec b$. Then the angle between $\vec a$ and $\vec c$ is:

Accepted Answer

$\vec a=8\vec b=-\dfrac87\vec c$, so $\vec a$ and $\vec c$ point in opposite directions --- the angle between them is $\pi$.

Solutions · 1