Calculus
posted by j .
1. Find a unit vector which is perpendicular to both of the vectors m=[4, 2, 3] and n=[2, 3, 1]

A vector perpendicular to both m and n is the cross product. After that, you only need to normalize it to make a unit vector.
Post if you need more help. 
 i j k 
 4 2 3 
 2 3 1 
= [7,10,16]/9√5
like this? please check if it's correct, thanks MathMate 
Correct!

thank you !