Angle Between Two Vectors

Monday, 26 March 2018

1:55 AM

Using the cosine rule

Since

Then;

 

 

 

Therefore,

Where

 

 

• Diving a vector by its length gives its value on a unit circle!

 

Examples

1. Find the angle between  and

 

 

 

2. Given the angle between  and  is , what is the angle between  and -?

The solution can simply be found through graphing. Else…

 OR

 

Given our range where , then .