# If #A = <2 ,4 ,-7 >#, #B = <3 ,8 ,2 ># and #C=A-B#, what is the angle between A and C?

##### 1 Answer

May 13, 2016

56.78 degrees

#### Explanation:

C = A-B = < (2-3), (4-8), (-7-2)> = <-1,-4,-9>

||A||=

||C||=

A.C= 2(-1) +4(-4) + (-7)(-9)= 45

If