# If #A = <4 ,3 ,-7 >#, #B = <5 ,8 ,-4 ># and #C=A-B#, what is the angle between A and C?

##### 1 Answer

Mar 13, 2016

87.75 deg, nearly.

#### Explanation:

A =

The

arc cos ( (A.C)/ (product of lengths A and C))

=