## 3psilon Group Title Two vectors A and B have magnitudes of 6m and make an angle of 60 degrees with each other. Find A DOT B. one year ago one year ago

1. zonazoo

$\cos \theta=\frac{ x \dot y }{ \left| x \right|\left| y \right|}$

2. zonazoo

so then just plug in your info, and solve for x dot y, or a dot b in this case.

3. 3psilon

How did you get the Cos theta = that stuff?

4. zonazoo

its just a theorem or an equation which comes from the law of cosines

5. 3psilon

So is it just 3?

6. zonazoo

well i took it when i first read it that A and B each had a magnitude of 6, but if they are 6 together, then yes it would be 3.

7. 3psilon

Oh they each have 6 So it would be 18>?

8. 3psilon

18