Easy Vector Question | Picture Included | Homework Help

[Ed Aboud]

Homework Statement

Check the picture.

Homework Equations

The Attempt at a Solution

I'm sure it's very simple but I just can't seem to get it. I've been sitting here staring at the page for a while now with no joy. Check the picture for my attempt.
Thanks very much for any help, greatly appreciated.

 

[Ed Aboud]

Can anyone help with this?

 

[rock.freak667]

well you are correct in saying that $\hat{b}=\frac{\vec{ab}}{|ab|}$ and that $\hat{c}=\frac{\vec{ac}}{|ac|}$.

and if $\vec{ad} = t( \hat{b} - \hat{c})$ what does that tell you about the direction of that vector?

How would you find the vector bc?

then how do you get the angle between two vector lines?

 

[Ed Aboud]

Ah I see it now so $\vec{ad} = t ( \hat{cb} )$
Therefore $\vec{ad}$ is perpendicular to $\hat{cb}$
Therefore $\vec{ad}$ is the perpendicular bisector of the the line bc.
Thank you very much for your help!