Two vectors are given by Avec = -1 i + 2 j and Bvec = 4 i + 2 j
Find A X B
Find the angle between A and B
The Attempt at a Solution
Okay well I got the First part of the problem, I know that A X B is -10, but when I do everything for the angle I keep getting the wrong answer.
After I finish with my calculating I come up with cos (theta) = -10/10 which would simplify to 180 degrees, but thats wrong...
Can someone please help me out, I dont understand where im going wrong