Distance between ( 3v3, -2) and ( v3,-2)

Question

When I found the distance I got 12 but the book is saying 2√3. It makes no sense because the step where I add the squares , isn't it supposed to be 12? 

 

So so the step where I added the squares : √(2√3)^2 + (0)^2 =12

Answer 1

This is the classic case of a question that is too simple for you to trust.  I see students fall for this all the time.  

 

There is no difference in the y-components, so only the difference in the x-components matter.  The distance formula is unnecessary, mere subtraction will do.

 

3√3 - √3 = 2√3