# If #A = <8 ,1 ,-7 >#, #B = <6 ,-2 ,5 >#, and #C=A-B#, what is the angle between A and C?

##### 1 Answer

Feb 18, 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,