# What is the angle between #<8,5,9 ># and #< 4,3,8 >#?

##### 1 Answer

The angle between two vectors depends on the sense of measurement. If

The formula for the angle between any two vectors

Here, # P = < 8, 5, 9 >, Q = < 4, 3, 8 >, P X Q = < 13, -26, 4 >, } P X Q } = sqrt 861, | P | = sqrt 170 and | Q | = sqrt 89.

The angle is

For measurement in the opposite sense, the angle is

Note that anticlockwise rotation for northern latitudes, with respect

to North Pole, is clockwise rotation for the southern latitodes with

respect to the South Pole.