# If #A = <-7 ,1 ,5 >#, #B = <3 ,6 ,1 ># and #C=A-B#, what is the angle between A and C?

##### 1 Answer

Apr 4, 2017

The angle is

#### Explanation:

Let's start by calculating

The angle between

Where

The dot product is

The modulus of

The modulus of

So,