# If #A = <2 ,-5 ,-4 >#, #B = <-9 ,1 ,9 ># and #C=A-B#, what is the angle between A and C?

##### 1 Answer

Mar 17, 2016

#### Explanation:

Angle between two vectors **U** and **V** is given by the formula

In the present case

**U** = **A** = <2,-5,-4> and **V** = **C** = **A** - **B** = <-11, 6, 13>

**U** . **V**= (2, -5,-4).(-11,6,-13) = -22 -30+52=0

|U|=

|V|=

Hence

Hence