Practice Final #4
npattison
So when finding the angle between the two vectors in the first part, do we take the absolute value of v dot w on the top?
JeffreyLam1: June 4, 2015, 11:08 p.m.
yes, since the absolute value of the dot product of two vectors is equal to their individual magnitudes times the angle between them.
Jerry_Zhongyang_Liu: June 5, 2015, 8:48 p.m.
If you limit the range of the angle to [0, pi/2], then you should add an absolute value to the dot product. The problem didn't ask you to do so, so you should not put an absolute value on it.