# If #A = <3 ,1 ,-1 >#, #B = <4 ,-7 ,-1 ># and #C=A-B#, what is the angle between A and C?

##### 1 Answer

Dec 18, 2016

The answer is

#### Explanation:

Lets start by calculating

The angle

The dot product

The modulus of

The modulus of

The angle is