# What is the angle between #<0,-7,6> # and #<-1,9,-3>#?

##### 1 Answer

Oct 19, 2016

#### Explanation:

We'll use the fact that the dot product

Dividing by

or

In our case, we have

If we calculate their magnitudes, we get

and

So, the formula we derived gives us

#=arccos(-81/sqrt(7735))#

#~~2.7414#