In: Advanced Math
Let u and v be orthogonal vectors in R3 and let w = 3u + 6v. Suppose that ||u|| = 5 and ||v|| = 4. Find the cosine of the angle between w and v.
and 
 are orthogonal vector of 
 then we have 
   
we have to find the angle between 
 and 
here   
the angle between two vector 
so we have to find out 
 and 
  
then we put the value and we got the angle between two vector

