# If #A = <3 ,-1 ,-8 >#, #B = <5 ,6 ,-9 ># and #C=A-B#, what is the angle between A and C?

##### 1 Answer

Dec 24, 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,