Vector Calculations | Find ⎮v-2w⎮

[MozAngeles]

Homework Statement

If ⎮v⎮=2, ⎮w⎮=3, and the angle between v and w is \pi/3[\tex], find ⎮v-2w⎮.<br /> <br /> <h2>Homework Equations</h2><br /> <br /> Im not sure how to go about this. maybe use \cos\theta[\tex]=u∙v/⎮u⎮⎮v⎮&lt;br /&gt; &lt;br /&gt; &lt;h2&gt;The Attempt at a Solution&lt;/h2&gt;&lt;br /&gt; i&amp;#039;m not sure where to start. i know this has to be pretty straightforward, but i don&amp;#039;t see it...&lt;br /&gt; anyt help would be nice thanks.

 

[tiny-tim]

Hi MozAngeles!

(write /tex not \tex )

hint: |v - 2w|² = (v - 2w).(v - 2w)